Journal articles on the topic 'OMPs'
To see the other types of publications on this topic, follow the link: OMPs.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'OMPs.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Puig, Marta, Carme Fusté, and Miquel Viñas. "Outer membrane proteins from Serratia marcescens." Canadian Journal of Microbiology 39, no. 1 (January 1, 1993): 108–11. http://dx.doi.org/10.1139/m93-015.
Full textAbstract:
The outer membrane proteins (OMPs) of several strains of Serratia marcescens have been studied by sodium dodecyl sulphate – urea – polyacrylamide gel electrophoresis. Four major OMPs, named Omp1, Omp2, Omp3, and OmpA (42, 40, 39, and 37 kDa, respectively), have been visualized. The relative proportions of Omp2 and Omp3 depend on cultural conditions (temperature of incubation, osmolarity, and nutrient availability).Key words: Serratia marcescens, outer membrane proteins, porin.
2
Noh, Susan M., Kelly A. Brayton, Donald P. Knowles, Joseph T. Agnes, Michael J. Dark, Wendy C. Brown, Timothy V. Baszler, and Guy H. Palmer. "Differential Expression and Sequence Conservation of the Anaplasma marginale msp2 Gene Superfamily Outer Membrane Proteins." Infection and Immunity 74, no. 6 (June 2006): 3471–79. http://dx.doi.org/10.1128/iai.01843-05.
Full textAbstract:
ABSTRACT Bacterial pathogens in the genera Anaplasma and Ehrlichia encode a protein superfamily, pfam01617, which includes the predominant outer membrane proteins (OMPs) of each species, major surface protein 2 (MSP2) and MSP3 of Anaplasma marginale and Anaplasma ovis, Anaplasma phagocytophilum MSP2 (p44), Ehrlichia chaffeensis p28-OMP, Ehrlichia canis p30, and Ehrlichia ruminantium MAP1, and has been shown to be involved in both antigenic variation within the mammalian host and differential expression between the mammalian and arthropod hosts. Recently, complete sequencing of the A. marginale genome has identified an expanded set of genes, designated omp1-14, encoding new members of this superfamily. Transcriptional analysis indicated that, with the exception of the three smallest open reading frames, omp2, omp3, and omp6, these superfamily genes are transcribed in A. marginale-infected erythrocytes, tick midgut and salivary glands, and the IDE8 tick cell line. OMPs 1, 4, 7 to 9, and 11 were confirmed to be expressed as proteins by A. marginale within infected erythrocytes, with expression being either markedly lower (OMPs 1, 4, and 7 to 9) or absent (OMP11) in infected tick cells, which reflected regulation at the transcript level. Although the pfam01617 superfamily includes the antigenically variable MSP2 and MSP3 surface proteins, analysis of the omp1-14 sequences throughout a cycle of acute and persistent infection in the mammalian host and tick transmission reveals a high degree of conservation, an observation supported by sequence comparisons between the St. Maries strain and Florida strain genomes.
3
Hellman, Judith, Paul M. Loiselle, Megan M. Tehan, Jennifer E. Allaire, Lenora A. Boyle, James T. Kurnick, David M. Andrews, Kwang Sik Kim, and H. Shaw Warren. "Outer Membrane Protein A, Peptidoglycan-Associated Lipoprotein, and Murein Lipoprotein Are Released by Escherichia coli Bacteria into Serum." Infection and Immunity 68, no. 5 (May 1, 2000): 2566–72. http://dx.doi.org/10.1128/iai.68.5.2566-2572.2000.
Full textAbstract:
ABSTRACT Complexes containing lipopolysaccharide (LPS) and three outer membrane proteins (OMPs) are released by gram-negative bacteria incubated in human serum and into the circulation in an experimental model of sepsis. The same OMPs are bound by immunoglobulin G (IgG) in the cross-protective antiserum raised to Escherichia coliJ5 (anti-J5 IgG). This study was performed to identify the three OMPs. The 35-kDa OMP was identified as outer membrane protein A (OmpA) by immunoblotting studies using OmpA-deficient bacteria and recombinant OmpA protein. The 18-kDa OMP was identified as peptidoglycan-associated lipoprotein (PAL) based on peptide sequences from the purified protein and immunoblotting studies using PAL-deficient bacteria. The 5- to 9-kDa OMP was identified as murein lipoprotein (MLP) based on immunoblotting studies using MLP-deficient bacteria. The studies identify the OMPs released into human serum and into the circulation in an experimental model of sepsis as OmpA, PAL, and MLP.
4
Yang, Chen, Sijia Peng, Chunlai Chen, and Xin Sheng Zhao. "Molecular mechanism of networking among DegP, Skp and SurA in periplasm for biogenesis of outer membrane proteins." Biochemical Journal 477, no. 16 (August 19, 2020): 2949–65. http://dx.doi.org/10.1042/bcj20200483.
Full textAbstract:
The biogenesis of outer membrane proteins (OMPs) is an extremely challenging process. In the periplasm of Escherichia coli, a group of quality control factors work together to exercise the safe-guard and quality control of OMPs. DegP, Skp and SurA are the three most prominent ones. Although extensive investigations have been carried out, the molecular mechanism regarding the networking among these proteins remains mostly mysterious. Our group has previously studied the molecular interactions of OMPs with SurA and Skp, using single-molecule detection (SMD). In this work, again using SMD, we studied how OmpC, a representative of OMPs, interacts with DegP, Skp and SurA collectively. Several important discoveries were made. The self-oligomerization of DegP to form hexamer occurs over hundred micromolars. When OmpC is in a monomer state at a low concentration, the OmpC·DegP6 and OmpC·DegP24 complexes form when the DegP concentration is around sub-micromolars and a hundred micromolars, respectively. High OmpC concentration promotes the binding affinity of DegP to OmpC by ∼100 folds. Skp and SurA behave differently when they interact synergistically with DegP in the presence of substrate. DegP can degrade SurA-protected OmpC, but Skp-protected OmpC forms the ternary complex OmpC·(Skp3)n·DegP6 (n = 1,2) to resist the DegP-mediated degradation. Combined with previous results, we were able to depict a comprehensive picture regarding the molecular mechanism of the networking among DegP, Skp and SurA in the periplasm for the OMPs biogenesis under physiological and stressed conditions.
5
Wu, Si, Xi Ge, Zhixin Lv, Zeyong Zhi, Zengyi Chang, and Xin Sheng Zhao. "Interaction between bacterial outer membrane proteins and periplasmic quality control factors: a kinetic partitioning mechanism." Biochemical Journal 438, no. 3 (August 26, 2011): 505–11. http://dx.doi.org/10.1042/bj20110264.
Full textAbstract:
The OMPs (outer membrane proteins) of Gram-negative bacteria have to be translocated through the periplasmic space before reaching their final destination. The aqueous environment of the periplasmic space and high permeability of the outer membrane engender such a translocation process inevitably challenging. In Escherichia coli, although SurA, Skp and DegP have been identified to function in translocating OMPs across the periplasm, their precise roles and their relationship remain to be elucidated. In the present paper, by using fluorescence resonance energy transfer and single-molecule detection, we have studied the interaction between the OMP OmpC and these periplasmic quality control factors. The results of the present study reveal that the binding rate of OmpC to SurA or Skp is much faster than that to DegP, which may lead to sequential interaction between OMPs and different quality control factors. Such a kinetic partitioning mechanism for the chaperone–substrate interaction may be essential for the quality control of the biogenesis of OMPs
6
Zhang, Shuang, Yu Cheng, Jing Ma, Yan Wang, Zengyi Chang, and Xinmiao Fu. "Degp degrades a wide range of substrate proteins in Escherichia coli under stress conditions." Biochemical Journal 476, no. 23 (December 3, 2019): 3549–64. http://dx.doi.org/10.1042/bcj20190446.
Full textAbstract:
DegP, a periplasmic dual-functional protease and chaperone in Gram-negative bacteria, is critical for bacterial stress resistance, but the precise underlying mechanisms are not fully understood. Here, we show that the protease function of DegP is critical for Escherichia coli cells to maintain membrane integrity, particularly under heat shock conditions (42°C). Site-directed photo-cross-linking, mass spectrometry and immunoblotting analyses reveal that both periplasmic proteins (e.g. OppA and MalE) and β-barrel outer membrane proteins (OMPs) are DegP-interacting proteins and that OppA is degraded by DegP in vitro and in vivo at 42°C. In addition, OmpA and BamA, chimeric β-barrel OMPs containing a soluble periplasmic domain, are bound to DegP in both unfolded and folded forms, whereas only the unfolded forms are degradable by DegP. The presence of folded OmpA as a substrate of DegP is attributed to its periplasmic domain, which is resistant to DegP degradation and even generally protects pure β-barrel OMPs from degradation in an intra-molecular way. Furthermore, a pair of residues (R262 and V328) in the PDZ domain-1 of DegP play important roles for binding unfolded and folded β-barrel OMPs, with R262 being critical. Our study, together with earlier reports, indicates that DegP plays a critical role in protein quality control in the bacterial periplasm by degrading both periplasmic proteins and β-barrel OMPs under stress conditions and likely also by participating in the folding of chimeric β-barrel OMPs. A working model is proposed to illustrate the finely tuned functions of DegP with respect to different substrate proteins.
7
Rodrigues, Inês C., Sílvia C. Rodrigues, Filipe V. Duarte, Paula M. da Costa, and Paulo M. da Costa. "The Role of Outer Membrane Proteins in UPEC Antimicrobial Resistance: A Systematic Review." Membranes 12, no. 10 (October 10, 2022): 981. http://dx.doi.org/10.3390/membranes12100981.
Full textAbstract:
Uropathogenic Escherichia coli (UPEC) are one of the most common agents of urinary tract infection. In the last decade, several UPEC strains have acquired antibiotic resistance mechanisms and some have become resistant to all classes of antibiotics. UPEC outer membrane proteins (OMPs) seem to have a decisive role not only in the processes of invasion and colonization of the bladder mucosa, but also in mechanisms of drug resistance, by which bacteria avoid killing by antimicrobial molecules. This systematic review was performed according to the PRISMA guidelines, aiming to characterize UPEC OMPs and identify their potential role in antimicrobial resistance. The search was limited to studies in English published during the last decade. Twenty-nine studies were included for revision and, among the 76 proteins identified, seven were associated with antibiotic resistance. Indeed, OmpC was associated with β-lactams resistance and OmpF with β-lactams and fluoroquinolone resistance. In turn, TolC, OmpX, YddB, TosA and murein lipoprotein (Lpp) were associated with fluoroquinolones, enrofloxacin, novobiocin, β-lactams and globomycin resistances, respectively. The clinical implications of UPEC resistance to antimicrobial agents in both veterinary and human medicine must propel the implementation of new strategies of administration of antimicrobial agents, while also promoting the development of improved antimicrobials, protective vaccines and specific inhibitors of virulence and resistance factors.
8
Mills, Scott D., Sharon R. Ruschkowski, Murry A. Stein, and B. Brett Finlay. "Trafficking of Porin-Deficient Salmonella typhimurium Mutants inside HeLa Cells: ompR andenvZ Mutants Are Defective for the Formation ofSalmonella-Induced Filaments." Infection and Immunity 66, no. 4 (April 1, 1998): 1806–11. http://dx.doi.org/10.1128/iai.66.4.1806-1811.1998.
Full textAbstract:
ABSTRACT Outer membrane porin genes of Salmonella typhimurium, including ompC, ompF, and tppB, are regulated by the products of ompB, a two-component regulatory locus encoding OmpR and EnvZ. S. typhimurium ompR mutants are attenuated in mice, but to date no one has studied the intracellular trafficking of S. typhimuriumporin-deficient mutants. In this study, isogenic transposon mutants ofS. typhimurium with insertions in ompR,envZ, ompF, ompC, ompD,osmZ, and tppB were compared with wild-type SL1344 for trafficking in the human epithelial cell line HeLa. We found that ompR and envZ mutants were reduced or completely inhibited for the formation ofSalmonella-induced filaments (Sifs). This result was confirmed with an ompB deletion mutant. Sifs are tubular structures containing lysosomal glycoprotein which are induced specifically by intracellular Salmonella. Genetic analysis showed that the ompR mutation could be complemented intrans by cloned ompR to restore its ability to induce Sifs. In contrast, mutations in the knownompR-regulated genes ompF, ompC, and tppB (as well as the ompR-independent porin gene, ompD) had no effect on Sif formation relative to that of wild-type SL1344, thus indicating that OmpR does not exert its role on these genes to induce Sif formation. The omp mutants studied were able to invade and replicate in HeLa cells at levels comparable to those in wild-type SL1344. We conclude that OmpR and EnvZ appear to regulate Sif formation triggered by intracellular S. typhimurium.
9
Engström, Patrik, Thomas P. Burke, Cuong J. Tran, Anthony T. Iavarone, and Matthew D. Welch. "Lysine methylation shields an intracellular pathogen from ubiquitylation and autophagy." Science Advances 7, no. 26 (June 2021): eabg2517. http://dx.doi.org/10.1126/sciadv.abg2517.
Full textAbstract:
Many intracellular pathogens avoid detection by their host cells. However, it remains unknown how they avoid being tagged by ubiquitin, an initial step leading to antimicrobial autophagy. Here, we show that the intracellular bacterial pathogen Rickettsia parkeri uses two protein-lysine methyltransferases (PKMTs) to modify outer membrane proteins (OMPs) and prevent their ubiquitylation. Mutants deficient in the PKMTs were avirulent in mice and failed to grow in macrophages because of ubiquitylation and autophagic targeting. Lysine methylation protected the abundant surface protein OmpB from ubiquitin-dependent depletion from the bacterial surface. Analysis of the lysine-methylome revealed that PKMTs modify a subset of OMPs, including OmpB, by methylation at the same sites that are modified by host ubiquitin. These findings show that lysine methylation is an essential determinant of rickettsial pathogenesis that shields bacterial proteins from ubiquitylation to evade autophagic targeting.
10
Zhou, Yan, Fu Wei Huang, Fa Rong Huang, and Lei Du. "Preparation and Properties of Silicon-Containing Arylacetylene Resins with Octa(maleimidophenyl)silsesquioxane." Advanced Materials Research 557-559 (July 2012): 1152–56. http://dx.doi.org/10.4028/www.scientific.net/amr.557-559.1152.
Full textAbstract:
Modified silicon-containing arylacetylene resins (DMSEPE-OMPS) were prepared from poly(dimethylsilyleneethynylenephenyleneethynylene) (DMSEPE) and Octa(maleimidophenyl)- silsesquioxane (OMPS). The curing reaction of DMSEPE-OMPS resin was studied by FT-IR and DSC techniques. Thermal stability and dielectric properties of cured DMSEPE-OMPS resins were determined. FT-IR and DSC analyses indicate that thermal polymerization of DMSEPE-OMPS resin occurs in the curing process. Thermal stabilities of cured DMSEPE-OMPS resins under N2 and air atmosphere decrease gradually with the increment of OMPS components. The incorporation of OMPS can obviously reduce dielectric constant of DMSEPE-OMPS resins.
11
Kissoyan, Kohar Annie, George F. Araj, and Ghassan M. Matar. "Prevalence of carbapenem resistance genes and corresponding MIC90 in Enterobacteriaceae at a tertiary care center in Lebanon." Journal of Infection in Developing Countries 12, no. 02.1 (February 22, 2018): 9S. http://dx.doi.org/10.3855/jidc.10097.
Full textAbstract:
Introduction: The aim of this study was to correlate genes involved in carbapenem resistance to MIC levels among clinical ESBL and non-ESBL producing carbapenem resistant Enterobacteriaceae (CRE) isolates of Escherichia coli and Klebsiella pneumoniae.
Methodology: E. coli (n = 76) and K. pneumoniae (n = 54), collected between July 2008 and July 2014, were analyzed. The MICs were determined against ertapenem (ERT), imipenem (IMP) and meropenem (MER). PCR was performed on all 130 isolates to amplify
the resistance and outer membrane proteins (OMPs) encoding genes: blaOXA-48, blaNDM-1, blaTEM-1, blaCTX-M-15, ompC and ompF. Sequencing was performed on selected isolates.
Results: The prevalence of blaOXA-48, blaNDM-1, blaTEM-1, and/or blaCTX-M-15 among E. coli isolates were 36%, 12%, 20% and 80%, respectively, while among K. pneumoniae they were 37%, 28%, 28% and 72%, respectively. K. pneumoniae isolates positive for any of these genes had an MIC90 > 32μg/mL against ERT, IMP and MER, while in E. coli isolates there was a variation in the MIC90 values. Porin impermeabilities were due to mutations in ompC and ompF genes in E. coli, and loss of ompC and ompF genes in K. pneumoniae, and increased MIC90 values.
Conclusion: The presence of more than one carbapenem resistance encoding gene and/or ESBL encoding gene did not have an effect on the MIC90 value in K. pneumoniae isolates, while in E. coli it showed higher MIC90 values.
12
Ayalew, Sahlu, Binu Shrestha, Marie Montelongo, Amanda E. Wilson, and Anthony W. Confer. "Immunogenicity of Mannheimia haemolytica Recombinant Outer Membrane Proteins Serotype 1-Specific Antigen, OmpA, OmpP2, and OmpD15." Clinical and Vaccine Immunology 18, no. 12 (October 5, 2011): 2067–74. http://dx.doi.org/10.1128/cvi.05332-11.
Full textAbstract:
ABSTRACTWe previously identifiedMannheimia haemolyticaouter membrane proteins (OMPs) that may be important immunogens by using immunoproteomic analyses. Genes for serotype 1-specific antigen (SSA-1), OmpA, OmpP2, and OmpD15 were cloned and expressed, and recombinant proteins were purified. Objective 1 of this study was to demonstrate immunogenicity of the four recombinant OMPs in mice and cattle. Objective 2 was to determine if the addition of individual recombinant OMPs or combinations of them would modify immune responsiveness of mice to the recombinant chimeric protein SAC89, containing the main epitope fromM. haemolyticaouter membrane lipoprotein PlpE and the neutralizing epitope ofM. haemolyticaleukotoxin. Mice vaccinated with recombinant OmpA (rOmpA), rSSA-1, rOmpD15, and rOmpP2 developed significant antibody responses toM. haemolyticaouter membranes and to the homologous recombinant OMP. Cattle vaccinated with rOmpA and rSSA-1 developed significant antibodies toM. haemolyticaouter membranes by day 28, whereas cattle vaccinated with rOmpD15 and rOmpP2 developed only minimal responses. Sera from cattle vaccinated with each of the recombinant proteins stimulated complement-mediated killing of the bacterium. Concurrent vaccination with SAC89 plus any of the four rOMPs singly resulted in increased endpoint anti-SAC89 titers, and for the SAC89/rSSA-1 vaccinees, the response was increased significantly. In contrast, the SAC89/P2/SSA-1 and SAC89/OmpA/P2/D15/SSA-1 combination vaccines resulted in significant decreases in anti-SAC89 antibodies compared to SAC89 vaccination alone. In conclusion, under the conditions of these experiments, vaccination of mice and cattle with rOmpA and rSSA-1 stimulated high antibody responses and may have protective vaccine potential.
13
Liu, Yi-Fang, Jing-Jou Yan, Huan-Yao Lei, Ching-Hao Teng, Ming-Cheng Wang, Chin-Chung Tseng, and Jiunn-Jong Wu. "Loss of Outer Membrane Protein C in Escherichia coli Contributes to Both Antibiotic Resistance and Escaping Antibody-Dependent Bactericidal Activity." Infection and Immunity 80, no. 5 (February 21, 2012): 1815–22. http://dx.doi.org/10.1128/iai.06395-11.
Full textAbstract:
ABSTRACTOuter membrane proteins (OMPs) serve as the permeability channels for nutrients, toxins, and antibiotics. InEscherichia coli, OmpA has been shown to be involved in bacterial virulence, and OmpC is related to multidrug resistance. However, it is unclear whether OmpC also has a role in the virulence ofE. coli. The aims of this study were to characterize the role of OmpC in antimicrobial resistance and bacterial virulence inE. coli. TheompCdeletion mutant showed significantly decreased susceptibility to carbapenems and cefepime. To investigate the survival ofE. coliexposed to the innate immune system, a human blood bactericidal assay showed that theompCmutant increased survival in blood and serum but not in complement-inactivated serum. These effects were also demonstrated in the natural selection of OmpC mutants. Also, C1q interacted withE. colithrough a complex of antibodies bound to OmpC as a major target. Bacterial survival was increased in the wild-type strain in a dose-dependent manner by adding free recombinant OmpC protein or anti-C1q antibody to human serum. These results demonstrated that the interaction of OmpC-specific antibody and C1q was the key step in initiating the antibody-dependent classical pathway for the clearance of OmpC-expressingE. coli. Anti-OmpC antibody was detected in human sera, indicating that OmpC is an immunogen. These data indicate that the loss of OmpC inE. coliis resistant to not only antibiotics, but also the serum bactericidal effect, which is mediated from the C1q and anti-OmpC antibody-dependent classical pathway.
14
Vasilkov, A., J. Joiner, and C. Seftor. "First results from a rotational Raman scattering cloud algorithm applied to the Suomi National Polar-orbiting Partnership (NPP) Ozone Mapping Profiler Spectrometer (OMPS) nadir mapper." Atmospheric Measurement Techniques Discussions 7, no. 3 (March 19, 2014): 2689–714. http://dx.doi.org/10.5194/amtd-7-2689-2014.
Full textAbstract:
Abstract. This paper reports initial results from an Ozone Mapping Profiler Suite (OMPS) nadir mapper cloud pressure and cloud fraction algorithm. The OMPS cloud products are intended for use in OMPS ozone or other trace-gas algorithms. We developed the OMPS cloud products using a heritage algorithm developed for the Ozone Monitoring Instrument (OMI) on NASA's Aura satellite. The cloud pressure algorithm utilizes the filling-in of ultra-violet solar Fraunhofer lines by rotational Raman scattering. The OMPS cloud products are evaluated by comparison with OMI cloud products that have been compared in turn with other collocated satellite data including cloud optical thickness profiles derived from a combination of measurements from the CloudSat radar and the MODIS imaging radiometer. We find that the probability density functions (PDFs) of effective cloud fraction retrieved from OMPS and OMI measurements are very similar. The PDFs of the OMPS and OMI cloud pressures are comparable. However, OMPS retrieves somewhat higher pressures on average. The current NASA total ozone retrieval algorithm makes use of a monthly gridded cloud pressure climatology developed from OMI. This climatology captures much of the variability associated with the relevant cloud pressures. However, the use of actual cloud pressures retrieved with OMPS in place of the OMI climatology appears to improve OMPS total column ozone estimates slightly.
15
Yu, Ding Sheng, Hong Wei Cao, and Ri Wei Xu. "The Effect of Octa(Maleimidophenyl)Silsesquioxane on Thermal and Dielectric Properties of Bismaleimide-Triazine Resins." Advanced Materials Research 47-50 (June 2008): 1161–64. http://dx.doi.org/10.4028/www.scientific.net/amr.47-50.1161.
Full textAbstract:
BT resins composed of 4,4’-bismaleimidodiphenylmethane (BMI) and 2,2’-bis-(4-cyanatophenyl)propane (BCE) were modified by octa(maleimidophenyl) silsesquioxane (OMPS). It was found that the curing reaction of BCE were accelerated by OMPS, and the onset temperature of the cyclotrimerization was reduced up to 95.5°C (by DSC). As demonstrated by DSC and FT-IR, there was no evidence indicated the co-reaction between maleimide and cyanate ester. 2,2’-diallyl bisphenol A (DBA) and diglycidyl ether of bisphenol A (E-51) were also used to enhance the toughness of BT resins, and the formulated BTA and BTE resins were obtained. The results of DMA and TG show that the BT, BTA, and BTE resins containing 1wt% of OMPS exhibit enhanced thermal properties in comparison with pristine BT0, BTA0, and BTE0 resins, while more content of OMPS may impair the polymer matrix, though the effect of OMPS was slight. The dielectric constant of these hybrid materials were reduced by incorporation of OMPS, while overmuch contents of OMPS were disadvantageous for dielectric constant due to the aggregation of OMPS.
16
Wei, Chun-Hai, Christiane Hoppe-Jones, Gary Amy, and TorOve Leiknes. "Organic micro-pollutants’ removal via anaerobic membrane bioreactor with ultrafiltration and nanofiltration." Journal of Water Reuse and Desalination 6, no. 3 (November 17, 2015): 362–70. http://dx.doi.org/10.2166/wrd.2015.138.
Full textAbstract:
The removal of 15 organic micro-pollutants (OMPs) in synthetic municipal wastewater was investigated in a laboratory-scale mesophilic anaerobic membrane bioreactor (AnMBR) using ultrafiltration and AnMBR followed by nanofiltration (NF), where powdered activated carbon (PAC) was added to enhance OMPs removal. No significant effects of OMPs spiking and NF connection on bulk organics removal and biogas production were observed. Amitriptyline, diphenhydramine, fluoxetine, sulfamethoxazole, TDCPP and trimethoprim showed readily biodegradable characteristics with consistent biological removal over 80%. Atrazine, carbamazepine, DEET, Dilantin, primidone and TCEP showed refractory characteristics with biological removal below 40%. Acetaminophen, atenolol and caffeine showed a prolonged adaption time of around 45 d, with initial biological removal below 40% and up to 50–80% after this period. Most readily biodegradable OMPs contained a strong electron donating group. Most refractory OMPs contained a strong electron withdrawing group or a halogen substitute. NF showed consistent high rejection of 80–92% with an average of 87% for all OMPs, which resulted in higher OMPs removal in AnMBR-NF than in AnMBR alone, especially for refractory OMPs. Limited sorption performance of PAC for OMPs removal was mainly due to low and batch dosage (100 mg/L) as well as the competitive sorption caused by bulk organics.
17
Vasilkov, A., J. Joiner, and C. Seftor. "First results from a rotational Raman scattering cloud algorithm applied to the Suomi National Polar-orbiting Partnership (NPP) Ozone Mapping and Profiler Suite (OMPS) Nadir Mapper." Atmospheric Measurement Techniques 7, no. 9 (September 10, 2014): 2897–906. http://dx.doi.org/10.5194/amt-7-2897-2014.
Full textAbstract:
Abstract. This paper reports initial results from an Ozone Mapping and Profiler Suite (OMPS) Nadir Mapper cloud pressure and cloud fraction algorithm. The OMPS cloud products are intended for use in OMPS ozone or other trace-gas algorithms. We developed the OMPS cloud products using a heritage algorithm developed for the Ozone Monitoring Instrument (OMI) on NASA's Aura satellite. The cloud pressure algorithm utilizes the filling-in of ultraviolet solar Fraunhofer lines by rotational Raman scattering. The OMPS cloud products are evaluated by comparison with OMI cloud products that have been compared in turn with other collocated satellite data including cloud optical thickness profiles derived from a combination of measurements from the CloudSat radar and MODerate-resolution Imaging Spectroradiometer (MODIS). We find that the probability density functions (PDFs) of effective cloud fraction retrieved from OMPS and OMI measurements are very similar. The PDFs of the OMPS and OMI cloud pressures are comparable. However, OMPS retrieves somewhat higher pressures on average. The current NASA total ozone retrieval algorithm makes use of a monthly gridded cloud pressure climatology developed from OMI. This climatology captures much of the variability associated with the relevant cloud pressures. However, the use of actual cloud pressures retrieved with OMPS in place of the OMI climatology changes OMPS total column ozone estimates locally (presumably in the correct direction) only in areas with large differences between climatological and actual cloud pressures. The ozone differences can be up to 5% in such areas.
18
NI, QINGSHAN, and LINGYUN ZOU. "ACCURATE DISCRIMINATION OF OUTER MEMBRANE PROTEINS USING SECONDARY STRUCTURE ELEMENT ALIGNMENT AND SUPPORT VECTOR MACHINE." Journal of Bioinformatics and Computational Biology 12, no. 01 (January 28, 2014): 1450003. http://dx.doi.org/10.1142/s0219720014500036.
Full textAbstract:
Outer membrane proteins (OMPs) play critical roles in many cellular processes and discriminating OMPs from other types of proteins is very important for OMPs identification in bacterial genomic proteins. In this study, a method SSEA_SVM is developed using secondary structure element alignment and support vector machine. Moreover, a novel kernel function is designed to utilize secondary structure information in the support vector machine classifier. A benchmark dataset, which consists of 208 OMPs, 673 globular proteins, and 206 α-helical membrane proteins, is used to evaluate the performance of SSEA_SVM. A high accuracy of 97.7% with 0.926 MCC is achieved while SSEA_SVM is applied to discriminating OMPs and non-OMPs. In comparison with existing methods in the literature, SSEA_SVM is also highly competitive. We suggest that SSEA_SVM is a much more promising method to identify OMPs in genomic proteins. A web server that implements SSEA_SVM is freely available at http://bioinfo.tmmu.edu.cn/SSEA_SVM/ .
19
Bai, K., C. Liu, R. Shi, and W. Gao. "Validation of the Suomi NPP Ozone Mapping and Profiler Suite total column ozone using Brewer and Dobson spectrophotometers." Atmospheric Measurement Techniques Discussions 6, no. 3 (May 23, 2013): 4577–605. http://dx.doi.org/10.5194/amtd-6-4577-2013.
Full textAbstract:
Abstract. This study mainly focuses on the validation of total column (TC) ozone data derived from the Ozone Mapping and Profiler Suite (OMPS) on board the NASA's Suomi National Polar-orbiting Partnership satellite (NPP). OMPS is an advanced suite of three hyperspectral instruments that maps global ozone on a daily basis and extends the more than 30 yr total ozone and ozone profile records. The algorithm used to derive OMPS TC ozone is adapted from the heritage of Total Ozone Mapping Spectrometer (TOMS) Version 7 algorithm but with a number of enhancements. Validation is primarily performed through comparisons with an ensemble of 74 global distributed Brewer and Dobson spectrophotometers measurements. Linear regression performs fair agreement between OMPS TC ozone and ground-based TC ozone measurements with root mean square error (RMSE) around of 3% (10 DU). Comparison shows that OMPS TC ozone estimates 0.21% higher than Brewer measurements average, with station-to-station standard deviation of 3.14%. As comparing with Dobson measurements, OMPS TC ozone averages 0.86% higher than the station average with standard deviation of 3.05%. The relative differences between OMPS and ground TC ozone were analysed varying with latitude and time as well as viewing geometry respectively. Comparisons show relative differences within 2% over most of latitude and viewing conditions. Only comparing with Brewer measurements did it show an OMPS TC ozone dependent error, large negative bias was observed as OMPS TC ozone below 220 DU and positive bias shown above 460 DU.
20
Darsouei, Reyhaneh, Javad Karimi, and Gary B. Dunphy. "Functional Characterization of Outer Membrane Proteins (OMPs) in Xenorhabdus nematophila and Photorhabdus luminescens through Insect Immune Defense Reactions." Insects 10, no. 10 (October 17, 2019): 352. http://dx.doi.org/10.3390/insects10100352.
Full textAbstract:
Xenorhabdus nematophila and Photorhabdus luminescens are entomopathogenic bacterial symbionts that produce toxic proteins that can interfere with the immune system of insects. Herein, we show that outer membrane proteins (OMPs) could be involved as bacterial virulence factors. Purified totals OMPs of both bacterial species were injected into fifth instar larvae of Spodoptera exigua Hübner. Larvae were surveyed for cellular defenses fluctuations in total haemocyte counts (THC) and granulocyte percentage and for the humoral defenses protease, phospholipase A2 (PLA2), and phenoloxidase (PO) activities at specific time intervals. Changes in the expression of the three inducible antimicrobial peptides (AMPs), cecropin, attacin, and spodoptericin, were also measured. Larvae treated with OMPs of both bacterial species had more haemocytes than did the negative controls. OMPs of X. nematophila caused more haemocyte destruction than did the OMPs of P. luminescens. The OMPs of both bacterial species initially activated insect defensive enzymes post-injection, the degree of activation varying with enzyme type. The AMPs, attacin, cecropin, and spodoptericin were up-regulated by OMP injections compared with the normal larvae. The expression of these three AMPs was maximal at four hours post injection (hpi) with P. luminescens OMPs treatment. Expression of the three AMPs in X. nematophila treated insects was irregular and lower than in the P. luminescens OMPs treatment. These findings provide insights into the role of OMPs of entomopathogenic nematode bacterial symbionts in countering the physiological defenses of insects.
21
Wang, Likun, Chunhui Pan, Banghua Yan, Trevor Beck, Junye Chen, Lihang Zhou, Satya Kalluri, and Mitch Goldberg. "Geolocation Assessment and Optimization for OMPS Nadir Mapper: Methodology." Remote Sensing 14, no. 13 (June 24, 2022): 3040. http://dx.doi.org/10.3390/rs14133040.
Full textAbstract:
Onboard both the Suomi National Polar-orbiting Partnership and Joint Polar Satellite System (JPSS) series of satellites, the Ozone Mapping and Profiler Suite Nadir Mapper (OMPS-NM) is a new generation of a total ozone column sensor and is used to generate total column ozone products. This study presents a method for efficiently assessing OMPS-NM geolocation accuracy using spatially collocated radiance measurements from the Visible Infrared Imaging Radiometer Suite (VIIRS) Moderate Band M1 by taking advantage of its high spatial resolution (750 m at nadir) and accurate geolocation. The basic idea is to find the best collocation position with maximum correlation between VIIRS collocated and real OMPS-NM radiances by perturbing OMPS-NM line-of-sight (LOS) vectors in the cross-track and along-track directions with small steps in the spacecraft coordinate. The perturbation angles at the best collocation position where OMPS-NM and VIIRS are optimally aligned are used to characterize OMPS-NM geolocation accuracy. In addition, the assessment results can be used to optimize the OMPS-NM field view angle lookup table in the Sensor Data Record (SDR) processing software to improve its geolocation accuracy. To demonstrate the methodology, the proposed method is successfully employed to evaluate OMPS-NM geolocation accuracy with different spatial resolutions. The results indicate that, after the view angle table was updated, the geolocation accuracy for both SNPP and NOAA-20 OMPS-NM is on the sub-pixel level (less than ¼ pixel size) along all the scan positions in both cross-track and along-track directions and the performance is very stable with time. The method proposed in this study lays down the framework for assessing the geolocation accuracy of future high-resolution OMPS-NM measurements.
22
Techawiwattanaboon, Teerasit, Praparat Thaibankluay, Chahya Kreangkaiwal, Suwitra Sathean-Anan-Kun, Prasong Khaenam, Jiradej Makjaroen, Trairak Pisitkun, and Kanitha Patarakul. "Surface proteomics and label-free quantification of Leptospira interrogans serovar Pomona." PLOS Neglected Tropical Diseases 15, no. 11 (November 29, 2021): e0009983. http://dx.doi.org/10.1371/journal.pntd.0009983.
Full textAbstract:
Leptospirosis is a re-emerging zoonosis with a global distribution. Surface-exposed outer membrane proteins (SE-OMPs) are crucial for bacterial–host interactions. SE-OMPs locate and expose their epitope on cell surface where is easily accessed by host molecules. This study aimed to screen for surface-exposed proteins and their abundance profile of pathogenic Leptospira interrogans serovar Pomona. Two complementary approaches, surface biotinylation and surface proteolytic shaving, followed by liquid chromatography tandem-mass spectrometry (LC-MS/MS) were employed to identify SE-OMPs of intact leptospires. For quantitative comparison, in-depth label-free analysis of SE-OMPs obtained from each method was performed using MaxQuant. The total number of proteins identified was 1,001 and 238 for surface biotinylation and proteinase K shaving, respectively. Among these, 39 were previously known SE-OMPs and 68 were predicted to be localized on the leptospiral surface. Based on MaxQuant analysis for relative quantification, six known SE-OMPs including EF- Tu, LipL21, LipL41, LipL46, Loa22, and OmpL36, and one predicted SE-OMPs, LipL71 were found in the 20 most abundant proteins, in which LipL41 was the highest abundant SE-OMP. Moreover, uncharacterized LIC14011 protein (LIP3228 ortholog in serovar Pomona) was identified as a novel predicted surface βb-OMP. High-abundance leptospiral SE-OMPs identified in this study may play roles in virulence and infection and are potential targets for development of vaccine or diagnostic tests for leptospirosis.
23
González Abad, Gonzalo, Alexander Vasilkov, Colin Seftor, Xiong Liu, and Kelly Chance. "Smithsonian Astrophysical Observatory Ozone Mapping and Profiler Suite (SAO OMPS) formaldehyde retrieval." Atmospheric Measurement Techniques 9, no. 7 (July 7, 2016): 2797–812. http://dx.doi.org/10.5194/amt-9-2797-2016.
Full textAbstract:
Abstract. This paper presents our new formaldehyde (H2CO) retrievals, obtained from spectra recorded by the nadir instrument of the Ozone Mapping and Profiler Suite (OMPS) flown on board NASA's Suomi National Polar-orbiting Partnership (SUOMI-NPP) satellite. Our algorithm is similar to the one currently in place for the production of NASA's Ozone Monitoring Instrument (OMI) operational H2CO product. We are now able to produce a set of long-term data from two different instruments that share a similar concept and a similar retrieval approach. The ongoing overlap period between OMI and OMPS offers a perfect opportunity to study the consistency between both data sets. The different spatial and spectral resolution of the instruments is a source of discrepancy in the retrievals despite the similarity of the physic assumptions of the algorithm. We have concluded that the reduced spectral resolution of OMPS in comparison with OMI is not a significant obstacle in obtaining good-quality retrievals. Indeed, the improved signal-to-noise ratio of OMPS with respect to OMI helps to reduce the noise of the retrievals performed using OMPS spectra. However, the size of OMPS spatial pixels imposes a limitation in the capability to distinguish particular features of H2CO that are discernible with OMI. With root mean square (RMS) residuals ∼ 5 × 10−4 for individual pixels we estimate the detection limit to be about 7.5 × 1015 molecules cm−2. Total vertical column density (VCD) errors for individual pixels range between 40 % for pixels with high concentrations to 100 % or more for pixels with concentrations at or below the detection limit. We compare different OMI products (SAO OMI v3.0.2 and BIRA OMI v14) with our OMPS product using 1 year of data, between September 2012 and September 2013. The seasonality of the retrieved slant columns is captured similarly by all products but there are discrepancies in the values of the VCDs. The mean biases among the two OMI products and our OMPS product are 23 % between OMI SAO and OMPS SAO and 28 % between OMI BIRA and OMPS SAO for eight selected regions.
24
González Abad, G., A. Vasilkov, C. Seftor, X. Liu, and K. Chance. "Smithsonian Astrophysical Observatory Ozone Mapping and Profiler Suite (SAO OMPS) formaldehyde retrieval." Atmospheric Measurement Techniques Discussions 8, no. 9 (September 7, 2015): 9209–40. http://dx.doi.org/10.5194/amtd-8-9209-2015.
Full textAbstract:
Abstract. This paper presents our new formaldehyde (H2CO) retrievals, obtained from spectra recorded by the nadir instrument of the Ozone Mapping and Profiler Suite (OMPS) flown on-board NASA's Suomi National Polar-orbiting Partnership (SUOMI-NPP) satellite. Our algorithm is similar to the one currently in place for the production of NASA's Ozone Monitoring Instrument (OMI) operational H2CO product. We are now able to produce a consistent set of long term data from two different instruments that share a similar concept. The ongoing overlap period between OMI and OMPS offers a perfect opportunity to study the consistency between both data sets. The different spatial and spectral resolution of the instruments is a source of discrepancy in the retrievals despite the similarity of the physic assumptions of the algorithm. We have concluded that the reduced spectral resolution of OMPS in comparison with OMI is not a significant obstacle in obtaining good quality retrievals. Indeed, the improved signal to noise ratio (SNR) of OMPS with respect to OMI helps to reduce the noise of the retrievals performed using OMPS spectra. However, the size of OMPS spatial pixels imposes a limitation in the capability to distinguish particular features of H2CO that are discernible with OMI. With root mean square (RMS) residuals ~ 5 × 10−4 for individual pixels we estimate the detection limit to be about 7.5 × 1015 molecules cm−2. Total vertical column densities (VCD) errors for individual pixels range between 40 % for pixels with high concentrations to 100 % or more for pixels with concentrations at or below the detection limit. We compare different OMI products with our OMPS product using one year of data, between September 2012 and September 2013. The seasonality of the retrieved slant columns is captured similarly by all products but there are discrepancies in the values of the VCDs. The mean biases among the two OMI products and our OMPS product are 21 % between OMI SAO and OMPS SAO and 38 % between OMI BIRA and OMPS SAO for eight selected regions.
25
Park, Geonung, Kyunghun Park, and Bonggeun Song. "Spatio-Temporal Change Monitoring of Outside Manure Piles Using Unmanned Aerial Vehicle Images." Drones 5, no. 1 (December 23, 2020): 1. http://dx.doi.org/10.3390/drones5010001.
Full textAbstract:
Water quality deterioration due to outdoor loading of livestock manure requires efficient management of outside manure piles (OMPs). This study was designed to investigate OMPs using unmanned aerial vehicles (UAVs) for efficient management of non-point source pollution in agricultural areas. A UAV was used to acquire image data, and the distribution and cover installation status of OMPs were identified through ortho-images; the volumes of OMP were calculated using digital surface model (DSM). UAV- and terrestrial laser scanning (TLS)-derived DSMs were compared for identifying the accuracy of calculated volumes. The average volume accuracy was 92.45%. From April to October, excluding July, the monthly average volumes of OMPs in the study site ranged from 64.89 m3 to 149.69 m3. Among the 28 OMPs investigated, 18 were located near streams or agricultural waterways. Establishing priority management areas among the OMP sites distributed in a basin is possible using spatial analysis, and it is expected that the application of UAV technology will contribute to the efficient management of OMPs and other non-point source pollutants.
26
Miętka, K., K. Brzostek, K. Guz-Regner, and G. Bugla-Płoskońska. "The mechanisms of complement activation in normal bovine serum and normal horse serum against Yersinia enterocolitica O:9 strains with different outer membrane proteins content." Polish Journal of Veterinary Sciences 19, no. 1 (March 1, 2016): 99–107. http://dx.doi.org/10.1515/pjvs-2016-0013.
Full textAbstract:
AbstractYersinia enterocolitica is a common zoonotic pathogen and facultative intracellular bacterium which can survive within blood cells. Cattle and horses are considered a reservoir of Y. enterocolitica which often causes several serious syndromes associated with yersiniosis such as abortions, premature births or infertility. The aim of our investigation was to determine the vitality of Y. enterocolitica O:9 strains (Ye9) in bovine and horse sera (NBS and NHrS) and explain the role of outer membrane proteins (OMPs) in serum resistance of these bacteria. Our previous studies demonstrated moderate human serum (NHS) resistance of the wild type Ye9 strain, whereas mutants lacking YadA, Ail or OmpC remained sensitive to the bactericidal activity of NHS. The present study showed that the wild type of Ye9 strain was resistant to the bactericidal activity of both NHrS and NBS, while Ye9 mutants lacking the YadA, Ail and OmpC proteins were sensitive to NHrS and NBS as well as to NHS. The mechanisms of complement activation against Ye9 strains lacking Ail and YadA were distinguished, i.e. activation of the classical/lectin pathways decisive in the bactericidal mechanism of complement activation of NBS, parallel activation of the classical/lectin and alternative pathways of NHrS. In this research the mechanism of independent activation of the classical/lectin or the alternative pathway of NBS and NHrS against Ye9 lacking OmpC porin was also established. The results indicate that serum resistance of Ye9 is multifactorial, in which extracellular structures, i.e. outer membrane proteins (OMPs) such as Ail, OmpC or YadA, play the main role.
27
Renu, Sankar, Ashley D. Markazi, Santosh Dhakal, Yashavanth Shaan Lakshmanappa, Revathi Shanmugasundaram, Ramesh K. Selvaraj, and Gourapura J. Renukaradhya. "Engineering of Targeted Mucoadhesive Chitosan Based Salmonella Nanovaccine for Oral Delivery in Poultry." Journal of Immunology 200, no. 1_Supplement (May 1, 2018): 118.15. http://dx.doi.org/10.4049/jimmunol.200.supp.118.15.
Full textAbstract:
Abstract Salmonellosis in poultry is a serious economic burden. The major concern is the public health hazard by consumption of salmonella contaminated poultry meat and egg. Currently used salmonella vaccines are ineffective in combating the Salmonellosis of chicken thus warranting the need of a potent vaccine, especially an oral vaccine that can elicit robust local intestinal immunity. Biodegradable and biocompatible natural polymers are FDA approved vehicles for vaccine delivery. We prepared a candidate subunit chitosan nanoparticle vaccine containing the immunogenic outer membrane proteins (OMPs) and flagellar (F) protein of salmonella, and surface decorated with F-protein (OMPs-F-CS NPs). Physicochemical and biocompatibility properties of OMPs-F-CS NPs were studied in detail including its stability in stomach pH conditions. Salmonella targets the microfold (M) cells in the ileum Peyer’s patches (PPs) of chicken. We designed the oral OMPs-F-CS NPs vaccine to target ileal PPs to induce specific local intestinal immunity, and demonstrated that by ex vivo and in vivo studies. Layer chickens vaccinated orally with OMPs-F-CS NPs had significantly higher OMPs- specific intestinal mucosal antibody and OMPs-specific lymphocytes proliferation responses. Further, OMPs-F-CS NPs vaccination upregulated the expression of toll-like receptor (TLR) -2, TLR-4, IFN-g, IL-4 and GATA-3 mRNA levels in cecal tonsils of birds. In conclusion, we engineered chitosan based oral salmonella nanovaccine targeting intestinal PPs immune cells of birds, and demonstrated its ability to induce antigen specific mucosal antibody and T cell responses. Thus, our candidate oral salmonella vaccine has the potential to mitigate Salmonellosis in poultry.
28
Bak, Juseon, Xiong Liu, Jae-Hwan Kim, David P. Haffner, Kelly Chance, Kai Yang, and Kang Sun. "Characterization and correction of OMPS nadir mapper measurements for ozone profile retrievals." Atmospheric Measurement Techniques 10, no. 11 (November 15, 2017): 4373–88. http://dx.doi.org/10.5194/amt-10-4373-2017.
Full textAbstract:
Abstract. This paper verifies and corrects the Ozone Mapping and Profiler Suite (OMPS) nadir mapper (NM) level 1B v2.0 measurements with the aim of producing accurate ozone profile retrievals using an optimal-estimation-based inversion method to fit measurements in the spectral range 302.5–340 nm. The evaluation of available slit functions demonstrates that preflight-measured slit functions represent OMPS measurements well compared to derived Gaussian slit functions. Our initial OMPS fitting residuals contain significant wavelength and cross-track-dependent biases, resulting in serious cross-track striping errors in the tropospheric ozone retrievals. To eliminate the systematic component of the fitting residuals, we apply soft calibration to OMPS radiances. With the soft calibration the amplitude of fitting residuals decreases from ∼ 1 to 0.2 % over low and middle latitudes, and thereby the consistency of tropospheric ozone retrievals between OMPS and the Ozone Monitoring Instrument (OMI) is substantially improved. A common mode correction is also implemented for additional radiometric calibration; it improves retrievals especially at high latitudes where the amplitude of fitting residuals decreases by a factor of ∼ 2. We estimate the noise floor error of OMPS measurements from standard deviations of the fitting residuals. The derived error in the Huggins band ( ∼ 0.1 %) is twice the OMPS L1B measurement error. OMPS noise floor errors constrain our retrievals better, leading to improving information content of ozone and reducing fitting residuals. The final precision of the fitting residuals is less than 0.1 % in the low and middle latitudes, with ∼ 1 degrees of freedom for signal for the tropospheric ozone, meeting the general requirements for successful tropospheric ozone retrievals.
29
Vigh, Jozsef, Eduardo Solessio, Catherine W. Morgans, and Eric M. Lasater. "Ionic Mechanisms Mediating Oscillatory Membrane Potentials in Wide-Field Retinal Amacrine Cells." Journal of Neurophysiology 90, no. 1 (July 2003): 431–43. http://dx.doi.org/10.1152/jn.00092.2003.
Full textAbstract:
Particular types of amacrine cells of the vertebrate retina show oscillatory membrane potentials (OMPs) in response to light stimulation. Historically it has been thought the oscillations arose as a result of circuit properties. In a previous study we found that in some amacrine cells, the ability to oscillate was an intrinsic property of the cell. Here we characterized the ionic mechanisms responsible for the oscillations in wide-field amacrine cells (WFACs) in an effort to better understand the functional properties of the cell. The OMPs were found to be calcium (Ca2+) dependent; blocking voltage-gated Ca2+ channels eliminated the oscillations, whereas elevating extracellular Ca2+ enhanced them. Strong intracellular Ca2+ buffering (10 mM EGTA or bis-( o-aminophenoxy)- N,N,N′ ,N′-tetraacetic acid) eliminated any attenuation in the OMPs as well as a Ca2+-dependent inactivation of the voltage-gated Ca2+ channels. Pharmacological and immunohistochemical characterization revealed that WFACs express L- and N-type voltage-sensitive Ca2+ channels. Block of the L-type channels eliminated the OMPs, but ω-conotoxin GVIA did not, suggesting a different function for the N-type channels. The L-type channels in WFACs are functionally coupled to a set of calcium-dependent potassium ( K(Ca)) channels to mediate OMPs. The initiation of OMPs depended on penitrem-A-sensitive (BK) K(Ca) channels, whereas their duration is under apamin-sensitive (SK) K(Ca) channel control. The Ca2+ current is essential to evoke the OMPs and triggering the K(Ca) currents, which here act as resonant currents, enhances the resonance as an amplifying current, influences the filtering characteristics of the cell membrane, and attenuates the OMPs via CDI of the L-type Ca2+ channel.
30
Yan, Banghua, Chunhui Pan, Trevor Beck, Xin Jin, Likun Wang, Ding Liang, Lawrence Flynn, et al. "New Reprocessing towards Life-Time Quality-Consistent Suomi NPP OMPS Nadir Sensor Data Records (SDR): Calibration Improvements and Impact Assessments on Long-Term Quality Stability of OMPS SDR Data Sets." Remote Sensing 14, no. 13 (June 29, 2022): 3125. http://dx.doi.org/10.3390/rs14133125.
Full textAbstract:
The Nadir Mapper (NM) and Nadir Profiler (NP) within the Ozone Mapping and Profiler Suites (OMPS) are ultraviolet spectrometers to measure Earth radiance and Solar irradiance spectra from 300–380 nm and 250–310 nm, respectively. The OMPS NM and NP instruments flying on the Suomi-NPP (SNPP) satellite have provided over ten years of operational Sensor Data Records (SDRs) data sets to support a variety of OMPS Environmental Data Record (EDR) applications. However, the discrepancies of quality remain in the operational OMPS SDR data prior to 28 June 2021 due to changes in calibration algorithms associated with the calibration coefficient look-up tables (LUTs) during this period. In this study, we present results for the newly (v2) reprocessed SNPP OMPS NM and NP SDR data prior to 30 June 2021, which uses consistent calibration tables with improved accuracy. Compared with a previous (v1) reprocessing, this new reprocessing includes the improvements associated with the following updated tables or error correction: an updated stray light correction table for the NM, an off-nadir geolocation error correction for the NM, an artificial offset error correction in the NM dark processing code, and biweekly solar wavelength LUTs for the NP. This study further analyzes the impact of each improvement on the quality of the OMPS SDR data by taking advantage of the existing OMPS SDR calibration/validation studies. Finally, this study compares the v2 reprocessed OMPS data sets with the operational and the v1 reprocessed data sets. The results demonstrate that the new reprocessing significantly improves the accuracy and consistency of the life-time SNPP OMPS NM and NP SDR data sets. It also advances the uniformity of the data over the dichroic range from 300 to 310 nm between the NM and NP. The normalized radiance differences at the same wavelength between the NM and NP observations are reduced from 0.001 order (v1 reprocessing) or 0.01 order (operational processing) to 0.001 order or smaller. The v2 reprocessed data are archived in the NOAA CLASS data center with the same format as the operational data.
31
Gu, Bin, Haisheng Xie, Xuehong Zhang, and Zhilong Wang. "Merging of a chemical reaction with microbial metabolismviainverse phase transfer catalysis for efficient production of redMonascuspigments." Reaction Chemistry & Engineering 4, no. 8 (2019): 1447–58. http://dx.doi.org/10.1039/c9re00179d.
Full text
32
Zamora, Bernarda, Martina Garau, François Maignen, Phill O'Neill, and Jorge Mestre-Ferrandiz. "OP138 Access To Orphan Drugs In The United Kingdom And Other European Countries." International Journal of Technology Assessment in Health Care 33, S1 (2017): 64–65. http://dx.doi.org/10.1017/s0266462317001969.
Full textAbstract:
INTRODUCTION:Under the Orphan Regulation, the European Medicines Agency (EMA) intended to incentivize the research and development of new treatments for rare and life-threatening conditions. Marketing authorisation of orphan medicinal products (OMPs) by the EMA is only the first step, as medicines are made available to patients when reimbursement or Health Technology Assessment (HTA) decisions are implemented by national health systems. We analyzed the availability and access to OMPs in the United Kingdom (UK), France, Germany, Italy and Spain. We compared the availability, which is the possibility to prescribe a given OMP, to the access, which refers to the full or partial reimbursement by the public health service.METHODS:We collected data on launches, HTA decisions, any centralized commissioning and/or reimbursement decision for all the OMPs authorised since 2000 in the UK countries (England, Scotland and Wales), France, Germany, Italy and Spain.RESULTS:Since the Orphan Regulation inception, the EMA granted marketing authorization to 143 OMPs. These OMPs are most widely accessible in Germany and France. Reimbursement in Germany is immediate after authorization. France and Italy present a delay of 19 months from authorization to reimbursement, which is shorter than in other countries. In England, less than 50 percent of centrally authorised OMPs are routinely funded by the National Health Service (NHS), including one-third of these recommended by the National Institute for Health and Care Excellence (NICE), and those reimbursed via commissioning policies and the Cancer Drugs Fund.CONCLUSIONS:The assessment of degree of access to OMPs across Europe is limited by differences in the national HTA and reimbursement systems and the heterogeneous information made publicly available on their decisions. Nonetheless, our study suggests that the primary purpose to grant equal availability to OMPs to the patients in the Eropean Union via the implementation of the orphan regulation was partially achieved with important variations of access observed across the countries included in our study.
33
Lyu, Zhi Xin, and Xin Sheng Zhao. "Periplasmic quality control in biogenesis of outer membrane proteins." Biochemical Society Transactions 43, no. 2 (April 1, 2015): 133–38. http://dx.doi.org/10.1042/bst20140217.
Full textAbstract:
The β-barrel outer membrane proteins (OMPs) are integral membrane proteins that reside in the outer membrane of Gram-negative bacteria and perform a diverse range of biological functions. Synthesized in the cytoplasm, OMPs must be transported across the inner membrane and through the periplasmic space before they are assembled in the outer membrane. In Escherichia coli, Skp, SurA and DegP are the most prominent factors identified to guide OMPs across the periplasm and to play the role of quality control. Although extensive genetic and biochemical analyses have revealed many basic functions of these periplasmic proteins, the mechanism of their collaboration in assisting the folding and insertion of OMPs is much less understood. Recently, biophysical approaches have shed light on the identification of the intricate network. In the present review, we summarize recent advances in the characterization of these key factors, with a special emphasis on the multifunctional protein DegP. In addition, we present our proposed model on the periplasmic quality control in biogenesis of OMPs.
34
Chart, H., D. Conway, and B. Rowe. "Outer membrane characteristics of Salmonella enteritidis phage type 4 growing in chickens." Epidemiology and Infection 111, no. 3 (December 1993): 449–54. http://dx.doi.org/10.1017/s0950268800057174.
Full textAbstract:
SummaryStrains of Salmonella enteritidis belonging to phage type 4 (SE4) were grown in the peritoneal cavities of chickens, and without subculture on laboratory media examined for inducible in vivo phenotypic characteristics. These bacteria expressed three major outer membrane proteins (OMPs) of 33, 35 and 36 kilodaltons (kDa), and iron regulated OMPs of 74, 78 and 81 kDa. Bacteria growing in vivo did not express flagella, or fimbriae with a subunit molecular mass of 14 kDa (14 kDa fimbriae). Two OMPs of 55 and 23 kDa, expressed during culture in nutrient broth, were repressed during growth in chickens. Possession of a 38 MDa ‘mouse virulence’ plasmid did not influence the expression of OMPs, flagella or fimbriae. It was concluded that strains of SE4 growing in chicken tissues, use an enterobactin mediated iron uptake system to obtain ferric ions, do not express flagella or 14 kDa fimbriae and appear not to express novel OMPs involved in survival in vivo.
35
Pai, Suresh R., Yvonne Upshaw, and Shiva P. Singh. "Characterization of monoclonal antibodies to the outer membrane protein (OmpD) of Salmonella typhimurium." Canadian Journal of Microbiology 38, no. 11 (November 1, 1992): 1102–7. http://dx.doi.org/10.1139/m92-181.
Full textAbstract:
A panel of monoclonal antibodies, seven against the trimeric and seven against the monomeric forms to outer membrane protein D (OmpD) of Salmonella typhimurium were produced. The specificities of these monoclonal antibodies for the porin proteins of S. typhimurium and their cross-reactions with Salmonella porins OmpC and OmpF were determined by Western immunoblotting and enzyme-linked immunosorbent assay. We observed that OmpD shared more epitopes and had greater structural similarity with OmpC than with OmpF. Key words: Salmonella typhimurium, outer membrane protein, monoclonal antibody, trimeric, monomeric.
36
Henderson, Nadine, Phill O'Neill, and Martina Garau. "PP106 Twenty Years Of Orphan Medicines Regulation: Have Treatments Reached Patients In Need Across Europe And Canada?" International Journal of Technology Assessment in Health Care 37, S1 (December 2021): 19. http://dx.doi.org/10.1017/s0266462321001124.
Full textAbstract:
IntroductionThe European Union regulation for orphan medicinal products (OMPs) was introduced to improve the quality of treatments for patients with rare conditions. To mark 20 years of European Union OMP regulation, this study compared access to OMPs and the length of their reimbursement process in a set of European countries and Canadian provinces. Access refers to their full or partial reimbursement by the public health service.MethodsData were collated on European Medicines Agency orphan designation and marketing authorizations, health technology assessment (HTA) decisions and reimbursement decisions, and the respective dates of these events for all the OMPs centrally authorized in 14 European countries (Belgium, England, France, Germany, Hungary, Italy, the Netherlands, Norway, Poland, Scotland, Slovakia, Spain, Sweden, and Switzerland) and four Canadian provinces (Alberta, British Columbia, Ontario, and Quebec).ResultsSince the implementation of the OMPs Regulation in 2000, 215 OMPs obtained marketing authorization. We found that Germany had the highest level of coverage, with 91 percent of OMPs being reimbursed. The three countries with the lowest reimbursement rates were Poland, Hungary, and Norway (below 30%). We observed that Germany had the quickest time to reimbursement following marketing authorization, followed by Switzerland and Scotland. We observed that Poland, Hungary, and Slovakia consistently had the longest time to reimbursement.ConclusionsWe observed substantial variation in the levels and speed of national reimbursement of OMPs, particularly when comparing countries in Eastern and Western Europe, which suggests that an equity gap between the regions may be present. The data also indicated a trend toward faster times to reimbursement over the past 10 years.
37
Barel, Gilli, Alexandra Sirota, Hanne Volpin, and Edouard Jurkevitch. "Fate of Predator and Prey Proteins during Growth of Bdellovibrio bacteriovorus on Escherichia coli and Pseudomonas syringae Prey." Journal of Bacteriology 187, no. 1 (January 1, 2005): 329–35. http://dx.doi.org/10.1128/jb.187.1.329-335.2005.
Full textAbstract:
ABSTRACT A two-dimensional electrophoretic analysis of protein distribution followed by identification of selected proteins by mass spectrometry was performed on fresh bdellovibrio cultures containing attack phase cells of the predatory bacterium Bdellovibrio bacteriovorus strain 109J-1 and the remains of an Escherichia coli or a Pseudomonas syringae pv. tomato prey. Cleavage of the peptidoglycan-associated outer membrane proteins (OMPs) OmpA in E. coli and OprF in P. syringae occurred in both prey. The tryptic peptides obtained from the cleavage products of OmpA and OprF were all located within the 19-kDa pronase-resistant N-terminal parts of the corresponding proteins. The predator cell fraction was separated from the prey ghosts in fresh bdellovibrio cultures by centrifugation on a Percoll-sucrose cushion. Proteins from each fraction were separated by two-dimensional electrophoresis and identified by mass spectrometric analysis. As no prey OMP could be detected in the predator cell fraction, it was concluded that prey OMPs are not transferred to the predator, as had been suggested previously. However, a protein from the predator was found bound to ghost cell envelopes. This protein may correspond to a protein earlier suggested to be associated with the prey outer or cytoplasmic membranes. Along with recently described polypeptides from B. bacteriovorus strains 100 and 114, it forms a new family of putative outer membrane proteins.
38
Farooq, S., S. A. Wani, S. Qureshi, M. A. Bhat, Z. A. Kashoo, and I. Hussain. "Identification of Immunodominant Outer Membrane Proteins of Fusobacterium necrophorum from Severe Ovine Footrot By MALDI-TOF Mass Spectrometry." Current Microbiology 78, no. 4 (February 27, 2021): 1298–304. http://dx.doi.org/10.1007/s00284-021-02383-2.
Full textAbstract:
AbstractThe aim of this study was to identify the immunodominant outer membrane proteins (OMPs) of Fusobacterium necrophorum from sheep affected with severe foot-rot. The OMP profile of ovine strains of F. necrophorum has not been well studied. We analyzed the OMP profile of the most frequent lktA variant JKS-F3 of F. necrophorum associated with severe ovine foot-rot with lesion score 4 in order to identify its major immunodominant OMPs. Electrophoretic separations of extracted OMPs showed a number of spots in two-dimensional electrophoretic gels. Two immunoreactive proteins of size around 43 kDa were identified through western blotting using hyperimmune sera raised in rabbits. These two immunogenic OMPs were analyzed by Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF/MS) which revealed that these two OMPs of lktA variant JKS-F3 of F. necrophorum showed 46 and 42 percent protein sequence coverage and scores of 125 and 114, respectively, with the reported 43 kDa outer membrane protein of F. necrophorum strain H05, a putative porin having properties similar to pore-forming proteins of anaerobic Gram-negative bacteria. These identified immunogenic OMPs will contribute to our understanding of the pathogenic role played by this organism in ovine foot-rot and could be exploited to devise an effective control strategy through development of an OMP-based recombinant vaccine to mitigate foot-rot in sheep and goats.
39
Maguire, Orla, Laura McCullagh, Cara Usher, and Michael Barry. "OP65 Pharmacoeconomic Evaluation Of Orphan Drugs: Impact Of Extra Criteria?" International Journal of Technology Assessment in Health Care 35, S1 (2019): 16. http://dx.doi.org/10.1017/s0266462319001260.
Full textAbstract:
IntroductionThere is ongoing debate as to whether conventional pharmacoeconomic evaluation (PE) methods are appropriate for orphan medicinal products (OMPs). The National Centre for Pharmacoeconomics (NCPE) in Ireland has a well-defined process for conducting pharmacoeconomic evaluations of pharmaceuticals, which is the same for OMPs and non-OMPs. The objective of this study was to identify whether supplementary criteria considered in the pharmacoeconomic evaluation of OMPs would affect final reimbursement recommendations.MethodsA literature search was conducted to identify criteria. Orphan drug pharmacoeconomic evaluations completed by the NCPE between January 2015 and December 2017 were identified and supplementary criteria, where feasible, were applied.ResultsFourteen pharmacoeconomic evaluations were included in the study. Three criteria that could feasibly be applied to the NCPE evaluation process were identified, all three of which essentially broadened the economic perspective of the pharmacoeconomic evaluation. Higher cost-effectiveness threshold: Despite being arbitrarily raised from EUR 45,000/QALY to EUR 100,000/QALY, only one orphan drug demonstrated cost-effectiveness at this higher threshold. Weighted QALY gain: here, a weighted gain of between one and three is applied to drugs demonstrating QALY gains between 10 and 30, respectively. No OMPs included in the study showed a QALY gain of more than 10. Thirteen demonstrated QALY gains less than 10 and one could not be evaluated. Societal perspective: six submissions incorporated societal perspective as a scenario analysis. Despite incremental cost-effectiveness ratios (ICERs) being reduced between 4 percent and 58 percent, only two OMPs demonstrated cost-effectiveness at the higher threshold (EUR 100,000/QALY).ConclusionsApplication of supplementary criteria to the pharmacoeconomic evaluation of OMPs had a minor effect on three products assessed. However, for the majority, the final cost-effectiveness outcomes remained the same. The study highlights that other criteria are being considered in the decision to reimburse.
40
Macmillan, Henriette, Junzo Norimine, Kelly A. Brayton, Guy H. Palmer, and Wendy C. Brown. "Physical Linkage of Naturally Complexed Bacterial Outer Membrane Proteins Enhances Immunogenicity." Infection and Immunity 76, no. 3 (December 17, 2007): 1223–29. http://dx.doi.org/10.1128/iai.01356-07.
Full textAbstract:
ABSTRACTThe outer membrane proteins (OMPs) of bacterial pathogens are essential for their growth and survival and especially for attachment and invasion of host cells. Since the outer membrane is the interface between the bacterium and the host cell, outer membranes and individual OMPs are targeted for development of vaccines against many bacterial diseases. Whole outer membrane fractions often protect against disease, and this protection cannot be fully reproduced by using individual OMPs. Exactly how the interactions among individual OMPs influence immunity is not well understood. We hypothesized that one OMP rich in T-cell epitopes can act as a carrier for an associated OMP which is poor in T-cell epitopes to generate T-dependent antibody responses, similar to the hapten-carrier effect. Major surface protein 1a (MSP1a) and MSP1b1 occur as naturally complexed OMPs in theAnaplasma marginaleouter membrane. Previous studies demonstrated that immunization with the native MSP1 heteromer induced strong immunoglobulin G (IgG) responses to both proteins, but only MSP1a stimulated strong CD4+T-cell responses. Therefore, to test our hypothesis, constructs of CD4+T-cell epitopes from MSP1a linked to MSP1b1 were compared with individually administered MSP1a and MSP1b1 for induction of MSP1b-specific IgG. By linking the T-cell epitopes from MSP1a to MSP1b1, significantly higher IgG titers against MSP1b1 were induced. Understanding how the naturally occurring intermolecular interactions between OMPs influence the immune response may lead to more effective vaccine design.
41
Kramarova, N. A., E. R. Nash, P. A. Newman, P. K. Bhartia, R. D. McPeters, D. F. Rault, C. J. Seftor, P. Q. Xu, and G. J. Labow. "Measuring the Antarctic ozone hole with the new Ozone Mapping and Profiler Suite (OMPS)." Atmospheric Chemistry and Physics 14, no. 5 (March 6, 2014): 2353–61. http://dx.doi.org/10.5194/acp-14-2353-2014.
Full textAbstract:
Abstract. The new Ozone Mapping and Profiler Suite (OMPS), which launched on the Suomi National Polar-orbiting Partnership satellite in October 2011, gives a detailed view of the development of the Antarctic ozone hole and extends the long series of satellite ozone measurements that go back to the early 1970s. OMPS includes two modules – nadir and limb – to measure profile and total ozone concentrations. The new limb module is designed to measure the vertical profile of ozone between the lowermost stratosphere and the mesosphere. The OMPS observations over Antarctica show excellent agreement with the measurements obtained from independent satellite and ground-based instruments. This validation demonstrates that OMPS data can ably extend the ozone time series over Antarctica in the future. The OMPS observations are used to monitor and characterize the evolution of the 2012 Antarctic ozone hole. While large ozone losses were observed in September 2012, a strong ozone rebound occurred in October and November 2012. This ozone rebound is characterized by rapid increases of ozone at mid-stratospheric levels and a splitting of the ozone hole in early November. The 2012 Antarctic ozone hole was the second smallest on record since 1988.
42
Martínez-Flores, Irma, Roxana Cano, Víctor H. Bustamante, Edmundo Calva, and JoséLuis Puente. "The ompB Operon Partially Determines Differential Expression of OmpC in Salmonella typhi andEscherichia coli." Journal of Bacteriology 181, no. 2 (January 15, 1999): 556–62. http://dx.doi.org/10.1128/jb.181.2.556-562.1999.
Full textAbstract:
ABSTRACT Expression of the Escherichia coli OmpC and OmpF outer membrane proteins is regulated by the osmolarity of the culture media. In contrast, expression of OmpC in Salmonella typhi is not influenced by osmolarity, while OmpF is regulated as in E. coli. To better understand the lack of osmoregulation of OmpC expression in S. typhi, we compared the expression of theompC gene in S. typhi and E. coli, using ompC-lacZ fusions and outer membrane protein (OMP) electrophoretic profiles. S. typhi ompC expression levels in S. typhi were similar at low and high osmolarity along the growth curve, whereas osmoregulation of E. coli ompC inE. coli was observed during the exponential phase. Both genes were highly expressed at high and low osmolarity when present inS. typhi, while expression of both was regulated by osmolarity in E. coli. Complementation experiments with either the S. typhi or E. coli ompB operon in an S. typhi ΔompB strain carrying theompC-lacZ fusions showed that both S. typhi andE. coli ompC were not regulated by osmolarity when they were under the control of S. typhi ompB. Interestingly, in the same strain, both genes were osmoregulated under E. coli ompB. Surprisingly, in E. coli ΔompB, they were both osmoregulated under S. typhi or E. coli ompB. Thus, the lack of osmoregulation of OmpC expression inS. typhi is determined in part by the ompBoperon, as well as by other unknown trans-acting elements present in S. typhi.
43
Futoma-Kołoch, Bożena, Gabriela Bugla-Płoskońska, Bartłomiej Dudek, Agata Dorotkiewicz-Jach, Zuzanna Drulis-Kawa, and Andrzej Gamian. "Outer Membrane Proteins of Salmonella as Potential Markers of Resistance to Serum, Antibiotics and Biocides." Current Medicinal Chemistry 26, no. 11 (June 28, 2019): 1960–78. http://dx.doi.org/10.2174/0929867325666181031130851.
Full textAbstract:
Salmonellosis continues to be a significant worldwide health problem. Despite rapid progress in identifying mechanisms of Salmonella virulence and resistance to chemicals, our knowledge of these mechanisms remains limited. Furthermore, it appears that the resistance to antibiotics can be amplified by ubiquitous usage of the disinfectants (biocides), both by industry and by ordinary households. Salmonella, as other Gram-negative bacteria possess outer membrane proteins (OMPs), which participate in maintaining cell integrity, adapting to environment, and interacting with infected host. Moreover, the OMPs may also contribute to resistance to antibacterials. This review summarizes the role of OMPs in Salmonella serum resistance, antibiotics resistance and cross-resistance to biocides. Although collected data do not allow to assign OMPs as markers of the Salmonella susceptibility to the above-mentioned factors, some of these proteins retain a dominant presence in certain types of resistance.
44
Joppi, Roberta. "European and Italian regulation on orphan medicinal products." Farmeconomia. Health economics and therapeutic pathways 14, no. 2 (March 22, 2013): 89–98. http://dx.doi.org/10.7175/fe.v14i2.633.
Full textAbstract:
The paper presents an overview of the European and Italian Regulation on Orphan Medicinal Products (OMPs), along with some data on the OMPs licensed in the EU from 2000 to 2012. The EU legislation encourages pharmaceutical companies to develop drugs for rare diseases, so-called “orphan drugs”. The European Medicine Agency recognizes orphan drug status mainly on the basis of the prevalence of the disease (≤ 5/10,000), and potential benefit. Orphan status implies incentives for pharmaceutical companies. From 2000 up to 2012 890 candidate orphan drug designations received a positive opinion and the marketing authorization was granted to 72 OMPs corresponding to 80 different indications. Currently, 59 OMPs are available to Italian patients either because licensed to the market by the AIFA or included in the list of the L. 648/96. Despite of an encouraging regulation nearly all the currently estimated rare diseases still await treatments.
45
Chaudhary, Anu, Cassandra Kamischke, Mara Leite, Melissa A. Altura, Loren Kinman, Hemantha Kulasekara, Marie-Pierre Blanc, Guoxing Wang, Cox Terhorst, and Samuel I. Miller. "β-Barrel outer membrane proteins suppress mTORC2 activation and induce autophagic responses." Science Signaling 11, no. 558 (November 27, 2018): eaat7493. http://dx.doi.org/10.1126/scisignal.aat7493.
Full textAbstract:
The outer membranes of Gram-negative bacteria and mitochondria contain proteins with a distinct β-barrel tertiary structure that could function as a molecular pattern recognized by the innate immune system. Here, we report that purified outer membrane proteins (OMPs) from different bacterial and mitochondrial sources triggered the induction of autophagy-related endosomal acidification, LC3B lipidation, and p62 degradation. Furthermore, OMPs reduced the phosphorylation and therefore activation of the multiprotein complex mTORC2 and its substrate Akt in macrophages and epithelial cells. The cell surface receptor SlamF8 and the DNA-protein kinase subunit XRCC6 were required for these OMP-specific responses in macrophages and epithelial cells, respectively. The addition of OMPs to mouse bone marrow–derived macrophages infected withSalmonellaTyphimurium facilitated bacterial clearance. These data identify a specific cellular response mediated by bacterial and mitochondrial OMPs that can alter inflammatory responses and influence the killing of pathogens.
46
Salhi, Imed, Rose-Anne Boigegrain, Jan Machold, Christoph Weise, Axel Cloeckaert, and Bruno Rouot. "Characterization of New Members of the Group 3 Outer Membrane Protein Family of Brucella spp." Infection and Immunity 71, no. 8 (August 2003): 4326–32. http://dx.doi.org/10.1128/iai.71.8.4326-4332.2003.
Full textAbstract:
ABSTRACT Impairment of the omp25 gene in Brucella spp. leads to attenuated strains and confers protection to the host. Omp25 and Omp31, whose functions remain unknown, were the first characterized members of group 3 outer membrane proteins (Omps) (25 to 34 kDa). Recently, genomic and proteomic approaches identified five new putative members of this family, some of which are produced in B. melitensis or B. abortus. In the present study, using protein microsequencing, we identified new members of group 3 Omps proteins produced in B. suis. Since several monoclonal antibodies (MAbs) against Omp25 cross-reacted with other members of group 3 Omps, we also performed Western immunoblotting to compare wild-type B. suis with mutants systematically having B. suis omp25-related genes knocked out. We demonstrate the production of three paralogs of Omp31 and/or Omp25 in B. suis, and the existence of a common site of signal peptide cleavage (AXAAD), which is very similar to that present in the five homologous Omps of Bartonella quintana. The seven group 3 Omps were classified in four-subgroups on the basis of percentage amino acid sequence identities: Omp25 alone, the Omp25b-Omp25c-Omp25d cluster, the Omp31/31b subgroup, and the less related Omp22 protein (also called Omp3b). Together with previous data, our results demonstrate that all new members of group 3 Omps are produced in B. suis or in other Brucella species and we propose a nomenclature that integrates all of these proteins to facilitate the understanding of future Brucella interspecies study results.
47
Zhang, Yan, Can Li, Nickolay A. Krotkov, Joanna Joiner, Vitali Fioletov, and Chris McLinden. "Continuation of long-term global SO<sub>2</sub> pollution monitoring from OMI to OMPS." Atmospheric Measurement Techniques 10, no. 4 (April 20, 2017): 1495–509. http://dx.doi.org/10.5194/amt-10-1495-2017.
Full textAbstract:
Abstract. Over the past 20 years, advances in satellite remote sensing of pollution-relevant species have made space-borne observations an increasingly important part of atmospheric chemistry research and air quality management. This progress has been facilitated by advanced UV–vis spectrometers, such as the Ozone Monitoring Instrument (OMI) on board the NASA Earth Observing System (EOS) Aura satellite, and continues with new instruments, such as the Ozone Mapping and Profiler Suite (OMPS) on board the NASA–NOAA Suomi National Polar-orbiting Partnership (SNPP) satellite. In this study, we demonstrate that it is possible, using our state-of-the-art principal component analysis (PCA) retrieval technique, to continue the long-term global SO2 pollution monitoring started by OMI with the current and future OMPS instruments that will fly on the NOAA Joint Polar Satellite System (JPSS) 1, 2, 3, and 4 satellites in addition to SNPP, with a very good consistency of retrievals from these instruments. Since OMI SO2 data have been primarily used for (1) providing regional context on air pollution and long-range transport on a daily basis and (2) providing information on point emission sources on an annual basis after data averaging, we focused on these two aspects in our OMI–OMPS comparisons. Four years of retrievals (2012–2015) have been compared for three regions: eastern China, Mexico, and South Africa. In general, the comparisons show relatively high correlations (r = 0. 79–0.96) of daily regional averaged SO2 mass between the two instruments and near-unity regression slopes (0.76–0.97). The annual averaged SO2 loading differences between OMI and OMPS are small (< 0.03 Dobson unit (DU) over South Africa and up to 0.1 DU over eastern China). We also found a very good correlation (r = 0. 92–0.97) in the spatial distribution of annual averaged SO2 between OMI and OMPS over the three regions during 2012–2015. The emissions from ∼ 400 SO2 sources calculated with the two instruments also show a very good correlation (r = ∼ 0.9) in each year during 2012–2015. OMPS-detected SO2 point source emissions are slightly lower than those from OMI, but OMI–OMPS differences decrease with increasing strength of source. The OMI–OMPS SO2 mass differences on a pixel by pixel (daily) basis in each region can show substantial differences. The two instruments have a spatial correlation coefficient of 0.7 or better on < ∼ 50 % of the days. It is worth noting that consistent SO2 retrievals were achieved without any explicit adjustments to OMI or OMPS radiance data and that the retrieval agreement may be further improved by introducing a more comprehensive Jacobian lookup table than is currently used.
48
Kramarova, N. A., E. R. Nash, P. A. Newman, P. K. Bhartia, R. D. McPeters, D. F. Rault, C. J. Seftor, and P. Q. Xu. "Measuring the Antarctic ozone hole with the new Ozone Mapping and Profiler Suite (OMPS)." Atmospheric Chemistry and Physics Discussions 13, no. 10 (October 10, 2013): 26305–25. http://dx.doi.org/10.5194/acpd-13-26305-2013.
Full textAbstract:
Abstract. The new Ozone Mapping and Profiler Suite (OMPS) launched on the Suomi National Polar-orbiting Partnership satellite in October 2011 gives a more detailed view of the development of the Antarctic ozone hole than ever before. This instrumental suite extends the long series of satellite ozone measurements that go back to the early 1970s. The OMPS includes two modules – nadir and limb – to measure profile and total ozone concentrations. The new limb module is designed to measure the vertical profile of ozone between the lowermost stratosphere and the mesosphere. The OMPS observations over Antarctica show excellent agreement with the measurements obtained from independent satellite and ground-based instruments. This validation demonstrates that OMPS data can ably extend the ozone time series over Antarctica in the future. The OMPS observations are used to monitor and characterize the evolution of the 2012 Antarctic ozone hole. While large ozone losses were observed in September 2012, a strong ozone rebound occurred in October and November 2012. This ozone rebound is characterized by rapid increases of ozone at mid-stratospheric levels and a splitting of the ozone hole in early November. The 2012 Antarctic ozone hole was the second smallest on record since 1988.
49
Masuda, Takashi, Yukitaka Murakami, Toshihide Noguchi, and Fuminobu Yoshimura. "Effects of Various Growth Conditions in a Chemostat on Expression of Virulence Factors in Porphyromonas gingivalis." Applied and Environmental Microbiology 72, no. 5 (May 2006): 3458–67. http://dx.doi.org/10.1128/aem.72.5.3458-3467.2006.
Full textAbstract:
ABSTRACT Porphyromonas gingivalis, one of the gram-negative organisms associated with periodontal disease, possesses potential virulence factors, including fimbriae, proteases, and major outer membrane proteins (OMPs). In this study, P. gingivalis ATCC 33277 was cultured in a chemostat under hemin excess and presumably peptide-limiting conditions to better understand the mechanisms of expression of the virulence factors upon environmental changes. At higher growth rates, the amounts of FimA and the 75-kDa protein, forming long and short fimbriae, respectively, increased significantly, whereas gingipains decreased in amount and activity. In a nutrient-limited medium, lesser amounts of the above two fimbrial proteins were observed, whereas clear differences were not found in the amounts of gingipains. In addition, two-dimensional electrophoresis revealed that proteins in cells were generally fewer in number during nutrient-limited growth. Under aeration, a considerable reduction in gingipain activity was found, whereas several proteins associated with intact cells significantly increased. However, the expression of major OMPs, such as RagA, RagB, and the OmpA-like proteins, was almost constant under all conditions tested. These results suggest that P. gingivalis may actively control expression of several virulence factors to survive in the widely fluctuating oral environment.
50
Huysmans, Gerard H. M. "Folding outer membrane proteins independently of the β-barrel assembly machinery: an assembly pathway for multimeric complexes?" Biochemical Society Transactions 44, no. 3 (June 9, 2016): 845–50. http://dx.doi.org/10.1042/bst20160003.
Full textAbstract:
Since the discovery of the essential role of the β-barrel assembly machinery (BAM) for the membrane insertion of outer membrane proteins (OMPs) that are unrelated in sequence, members of this universally conserved family dominate discussions on OMP assembly in bacteria, mitochondria and chloroplasts. However, several multimeric bacterial OMPs assemble independently of the catalyzing BAM-component BamA. Recent progress on this alternative pathway is reviewed here, and a model for BAM-independent assembly for multimeric OMPs is proposed in which monomer delivery to the membrane and stable prepore formation are key steps towards productive membrane insertion.