Journal articles: 'Acidic oligopeptides'

1

Ishizaki, Junko, Yoshihiro Waki, Tatsuo Takahashi-Nishioka, Koichi Yokogawa, and Ken-ichi Miyamoto. "Selective drug delivery to bone using acidic oligopeptides." Journal of Bone and Mineral Metabolism 27, no. 1 (November 19, 2008): 1–8. http://dx.doi.org/10.1007/s00774-008-0004-z.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Morty, Rory E., Vilmos Fülöp, and Norma W. Andrews. "Substrate Recognition Properties of Oligopeptidase B from Salmonella enterica Serovar Typhimurium." Journal of Bacteriology 184, no. 12 (June 15, 2002): 3329–37. http://dx.doi.org/10.1128/jb.184.12.3329-3337.2002.

Full text

Abstract:

ABSTRACT Oligopeptidase B (OpdB) is a serine peptidase broadly distributed among unicellular eukaryotes, gram-negative bacteria, and spirochetes which has emerged as an important virulence factor and potential therapeutic target in infectious diseases. We report here the cloning and expression of the opdB homologue from Salmonella enterica serovar Typhimurium and demonstrate that it exhibits amidolytic activity exclusively against substrates with basic residues in P1. While similar to its eukaryotic homologues in terms of substrate specificity, Salmonella OpdB differs significantly in catalytic power and inhibition and activation properties. In addition to oligopeptide substrates, restricted proteolysis of histone proteins was observed, although no cleavage was seen at or near residues that had been posttranslationally modified or at defined secondary structures. This supports the idea that the catalytic site of OpdB may be accessible only to unstructured oligopeptides, similar to the closely related prolyl oligopeptidase (POP). Salmonella OpdB was employed as a model enzyme to define determinants of substrate specificity that distinguish OpdB from POP, which hydrolyzes substrates exclusively at proline residues. Using site-directed mutagenesis, nine acidic residues that are conserved in OpdBs but absent from POPs were converted to their corresponding residues in POP. In this manner, we identified a pair of glutamic acid residues, Glu576 and Glu578, that define P1 specificity and direct OpdB cleavage C terminal to basic residues. We have also identified a second pair of residues, Asp460 and Asp462, that may be involved in defining P2 specificity and thus direct preferential cleavage by OpdB after pairs of basic residues.

APA, Harvard, Vancouver, ISO, and other styles

3

Varga, V., R. Janáky, K. M. Marnela, J. Gulyás, P. Kontro, and S. S. Oja. "Displacement of excitatory amino acid receptor ligands by acidic oligopeptides." Neurochemical Research 14, no. 12 (December 1989): 1223–27. http://dx.doi.org/10.1007/bf00965513.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Imamura, Koreyoshi, Yuuki Kawasaki, Takeshi Nagayasu, Takaharu Sakiyama, and Kazuhiro Nakanishi. "Adsorption characteristics of oligopeptides composed of acidic and basic amino acids on titanium surface." Journal of Bioscience and Bioengineering 103, no. 1 (January 2007): 7–12. http://dx.doi.org/10.1263/jbb.103.7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

IENAGA, KAZUHARU, KO NAKAMURA, KUNIHIKO HIGASHIURA, YOSHIO TOYOMAKI, and HIROSHI KIMURA. "Simple peptides. III. Syntheses and properties of taurine-oligopeptides containing an acidic .ALPHA.-amino acid." CHEMICAL & PHARMACEUTICAL BULLETIN 36, no. 8 (1988): 2796–801. http://dx.doi.org/10.1248/cpb.36.2796.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Mosrin, C., M. Riva, M. Beltrame, E. Cassar, A. Sentenac, and P. Thuriaux. "The RPC31 gene of Saccharomyces cerevisiae encodes a subunit of RNA polymerase C (III) with an acidic tail." Molecular and Cellular Biology 10, no. 9 (September 1990): 4737–43. http://dx.doi.org/10.1128/mcb.10.9.4737-4743.1990.

Full text

Abstract:

The RPC31 gene encoding the C31 subunit of Saccharomyces cerevisiae RNA polymerase C (III) has been isolated, starting from a C-terminal fragment cloned on a lambda gt11 library. It is unique on the yeast genome and lies on the left arm of chromosome XIV, very close to a NotI site. Its coding sequence perfectly matches the amino acid sequence of two oligopeptides prepared from purified C31. It is also identical to the ACP2 gene previously described as encoding an HMG1-like protein (W. Haggren and D. Kolodrubetz, Mol. Cell. Biol. 8:1282-1289, 1988). Thus, ACP2 and RPC31 are allelic and encode a subunit of RNA polymerase C. The c31 protein has a highly acidic C-terminal tail also found in several other chromatin-interacting proteins, including animal HMG1. Outside this domain, however, there is no appreciable homology to any known protein. The growth phenotypes of a gene deletion, of insertions, and of nonsense mutations indicate that the C31 protein is strictly required for cell growth and that most of the acidic domain is essential for its function. Random mutagenesis failed to yield temperature-sensitive mutants, but a slowly growing mutant was constructed by partial suppression of a UAA nonsense allele of RPC31. Its reduced rate of tRNA synthesis in vivo relative to 5.8S rRNA supports the hypothesis that the C31 protein is a functional subunit of RNA polymerase C.

APA, Harvard, Vancouver, ISO, and other styles

7

Mosrin, C., M. Riva, M. Beltrame, E. Cassar, A. Sentenac, and P. Thuriaux. "The RPC31 gene of Saccharomyces cerevisiae encodes a subunit of RNA polymerase C (III) with an acidic tail." Molecular and Cellular Biology 10, no. 9 (September 1990): 4737–43. http://dx.doi.org/10.1128/mcb.10.9.4737.

Full text

Abstract:

The RPC31 gene encoding the C31 subunit of Saccharomyces cerevisiae RNA polymerase C (III) has been isolated, starting from a C-terminal fragment cloned on a lambda gt11 library. It is unique on the yeast genome and lies on the left arm of chromosome XIV, very close to a NotI site. Its coding sequence perfectly matches the amino acid sequence of two oligopeptides prepared from purified C31. It is also identical to the ACP2 gene previously described as encoding an HMG1-like protein (W. Haggren and D. Kolodrubetz, Mol. Cell. Biol. 8:1282-1289, 1988). Thus, ACP2 and RPC31 are allelic and encode a subunit of RNA polymerase C. The c31 protein has a highly acidic C-terminal tail also found in several other chromatin-interacting proteins, including animal HMG1. Outside this domain, however, there is no appreciable homology to any known protein. The growth phenotypes of a gene deletion, of insertions, and of nonsense mutations indicate that the C31 protein is strictly required for cell growth and that most of the acidic domain is essential for its function. Random mutagenesis failed to yield temperature-sensitive mutants, but a slowly growing mutant was constructed by partial suppression of a UAA nonsense allele of RPC31. Its reduced rate of tRNA synthesis in vivo relative to 5.8S rRNA supports the hypothesis that the C31 protein is a functional subunit of RNA polymerase C.

APA, Harvard, Vancouver, ISO, and other styles

8

Nakata, Takashi, Masatoshi Takahashi, Masaru Nakatani, Rie Kuramitsu, Masahiro Tamura, and Hideo Okai. "Role of Basic and Acidic Fragments in Delicious Peptides (Lys-Gly-Asp Glu-Glu-Ser-Leu-Ala) and the Taste Behavior of Sodium and Potassium Salts in Acidic Oligopeptides." Bioscience, Biotechnology, and Biochemistry 59, no. 4 (January 1995): 689–93. http://dx.doi.org/10.1271/bbb.59.689.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Song, L., M. Ye, M. Troyanovskaya, E. Wilk, S. Wilk, and D. P. Healy. "Rat kidney glutamyl aminopeptidase (aminopeptidase A): molecular identity and cellular localization." American Journal of Physiology-Renal Physiology 267, no. 4 (October 1, 1994): F546—F557. http://dx.doi.org/10.1152/ajprenal.1994.267.4.f546.

Full text

Abstract:

Glutamyl aminopeptidase [aminopeptidase A (EAP), EC 3.4.11.7] is an ectoenzyme that selectively hydrolyzes acidic amino acid residues from the amino terminus of oligopeptides. EAP activity is highest within the kidney and small intestine. The murine pre-B cell BP-1/6C3 and the human kidney glycoprotein gp160 differentiation antigens have been reported to have biochemical properties indistinguishable from EAP. It is not known, however, if rat kidney EAP is a homologue of these antigens or molecularly distinct. Using the reverse transcription-polymerase chain reaction method with oligonucleotide primers based on the BP-1/6C3 nucleotide sequence, we isolated a 450-bp partial cDNA from rat kidney poly(A)+ RNA. The partial cDNA encoded a predicted protein that was 92% and 86% identical to the murine BP-1/6C3 and human gp160 antigens, respectively; the amino acid sequence within the zinc-binding domain was completely conserved. Purification of EAP from rat kidney and microsequence analysis of a tryptic digest peptide fragment (18-mer) indicated that the fragment was highly similar to a region within the BP-1/6C3 and gp160 proteins. Northern blot hybridization and immunoblot analyses were also consistent with labeling of products the same size as reported for the BP-1/6C3 and gp160 antigens. There was a good correlation between the cellular distribution of EAP mRNA and EAP immunoreactivity, with proximal tubules and glomerular mesangial cells having the highest densities. These results indicate that rat kidney EAP is a species homologue of the murine BP-1/6C3 and human gp160 antigens. Furthermore, on the basis of its cellular localization, rat kidney EAP is likely to be involved in degradation of oligopeptides within the glomerulus and the glomerular filtrate. Since cells that express EAP also express receptors for angiotensin II, an intrarenal vasoactive hormone that is a substrate for EAP, these results further suggest that EAP may play a role in modulating the activity of intrarenal angiotensin II.

APA, Harvard, Vancouver, ISO, and other styles

10

Görnhardt, Birgit, Ila Rouhara, and Elmon Schmelzer. "Cyst Germination Proteins of the Potato Pathogen Phytophthora infestans Share Homology with Human Mucins." Molecular Plant-Microbe Interactions® 13, no. 1 (January 2000): 32–42. http://dx.doi.org/10.1094/mpmi.2000.13.1.32.

Full text

Abstract:

We have cloned genes of Phytophthora infestans, the causal agent of potato late blight, that are activated shortly before the onset of invasion of the host tissue. The three genes isolated appear to be arranged in a genomic cluster and belong to a small polymorphic gene family. A conspicuous feature of the deduced proteins is an internal octapeptide repeat with the consensus sequence TTYAP TEE. Because of this structural motif, these novel P. infestans proteins were named Car (cyst-germination-specific acidic repeat) proteins. One of the genes, car90, codes for 1,489 amino acids including 120 octapeptide tandem repeats. Car proteins are transiently expressed during germination of cysts and formation of appressoria and are localized at the surface of germlings. The structural motif of tandemly repeated oligopeptides also occurs in a prominent class of proteins, the mucins, from mammals. The P. infestans Car proteins share 51% sequence homology with the tandem repeat region of a subfamily of human mucins. According to the physiological functions ascribed to mucins, we suggest that Car proteins may serve as a mucous cover protecting the germling from desiccation, physical damage, and adverse effects of the plant defense response and may assist in adhesion to the leaf surface.

APA, Harvard, Vancouver, ISO, and other styles

11

Dalal, Seema, and Michael Klemba. "Roles for Two Aminopeptidases in Vacuolar Hemoglobin Catabolism in Plasmodium falciparum." Journal of Biological Chemistry 282, no. 49 (September 25, 2007): 35978–87. http://dx.doi.org/10.1074/jbc.m703643200.

Full text

Abstract:

During the erythrocytic stage of its life cycle, the human malaria parasite Plasmodium falciparum catabolizes large quantities of host-cell hemoglobin in an acidic organelle, the food vacuole. A current model for the catabolism of globin-derived oligopeptides invokes peptide transport out of the food vacuole followed by hydrolysis to amino acids by cytosolic aminopeptidases. To test this model, we have examined the roles of four parasite aminopeptidases during the erythrocytic cycle. Localization of tagged aminopeptidases, coupled with biochemical analysis of enriched food vacuoles, revealed the presence of amino acid-generating pathways in the food vacuole as well as the cytosol. Based on the localization data and in vitro assays, we propose a specific role for one of the plasmodial enzymes, aminopeptidase P, in the catabolism of proline-containing peptides in both the vacuole and the cytosol. We establish an apparent requirement for three of the four aminopeptidases (including the two food vacuole enzymes) for efficient parasite proliferation. To gain insight into the impact of aminopeptidase inhibition on parasite development, we examined the effect of the presence of amino acids in the culture medium of the parasite on the toxicity of the aminopeptidase inhibitor bestatin. The ability of bestatin to block parasite replication was only slightly affected when 19 of 20 amino acids were withdrawn from the medium, indicating that exogenous amino acids cannot compensate for the loss of aminopeptidase activity. Together, these results support the development of aminopeptidase inhibitors as novel chemotherapeutics directed against malaria.

APA, Harvard, Vancouver, ISO, and other styles

12

Nakazawa, Hikaru, Mitsuo Umetsu, Tatsuya Hirose, Takamitsu Hattori, and Izumi Kumagai. "Identification of Indium Tin Oxide Nanoparticle-Binding Peptides via Phage Display and Biopanning Under Various Buffer Conditions." Protein & Peptide Letters 27, no. 6 (June 9, 2020): 557–66. http://dx.doi.org/10.2174/0929866526666191113151934.

Full text

Abstract:

Background: By recent advances in phage-display approaches, many oligopeptides exhibiting binding affinities for metal oxides have been identified. Indium tin oxide is one of the most widely used conductive oxides, because it has a large band gap of 3.7–4.0 eV. In recent years, there have been reports about several ITO-based biosensors. Development of an ITO binding interface for the clustering of sensor proteins without complex bioconjugates is required. Objective: In this article, we aimed to identify peptides that bind to indium tin oxide nanoparticles via different binding mechanisms. Methods: Indium tin oxide nanoparticles binding peptide ware selected using phage display and biopanning against indium tin oxide, under five different buffer conditions and these peptides characterized about binding affinity and specificity. Results: Three types of indium tin oxide nanoparticles-binding peptides were selected from 10 types of peptide candidates identified in phage display and biopanning. These included ITOBP8, which had an acidic isoelectric point, and was identified when a buffer containing guanidine was used, and ITOBP6 and ITOBP7, which contained a His-His-Lys sequence at their N-termini, and were identified when a highly concentrated phosphate elution buffer with a low ionic strength was used. Among these peptides, ITOBP6 exhibited the strongest indium tin oxide nanoparticlesbinding affinity (dissociation constant, 585 nmol/L; amount of protein bound at saturation, 17.5 nmol/m 2 - particles). Conclusion: These results indicate that peptides with specific binding properties can be obtained through careful selection of the buffer conditions in which the biopanning procedure is performed.

APA, Harvard, Vancouver, ISO, and other styles

13

Leuthold, Simone, Bruno Hagenbuch, Nilufar Mohebbi, Carsten A. Wagner, Peter J. Meier, and Bruno Stieger. "Mechanisms of pH-gradient driven transport mediated by organic anion polypeptide transporters." American Journal of Physiology-Cell Physiology 296, no. 3 (March 2009): C570—C582. http://dx.doi.org/10.1152/ajpcell.00436.2008.

Full text

Abstract:

Organic anion transporting polypeptides (humans OATPs, rodents Oatps) are expressed in most mammalian tissues and mediate cellular uptake of a wide variety of amphipathic organic compounds such as bile salts, steroid conjugates, oligopeptides, and a large list of drugs, probably by acting as anion exchangers. In the present study we aimed to investigate the role of the extracellular pH on the transport activity of nine human and four rat OATPs/Oatps. Furthermore, we aimed to test the concept that OATP/Oatp transport activity is accompanied by extrusion of bicarbonate. By using amphibian Xenopus laevis oocytes expressing OATPs/Oatps and mammalian cell lines stably transfected with OATPs/Oatps, we could demonstrate that in all OATPs/Oatps investigated, with the exception of OATP1C1, a low extracellular pH stimulated transport activity. This stimulation was accompanied by an increased substrate affinity as evidenced by lower apparent Michaelis-Menten constant values. OATP1C1 is lacking a highly conserved histidine in the third transmembrane domain, which was shown by site-directed mutagenesis to be critically involved in the pH dependency of OATPs/Oatps. Using online intracellular pH measurements in OATP/Oatp-transfected Chinese Hamster Ovary (CHO)-K1 cells, we could demonstrate the presence of a 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid-sensitive chloride/bicarbonate exchanger in CHO-K1 cells and that OATP/Oatp-mediated substrate transport is paralleled by bicarbonate efflux. We conclude that the pH dependency of OATPs/Oatps may lead to a stimulation of substrate transport in an acidic microenvironment and that the OATP/Oatp-mediated substrate transport into cells is generally compensated or accompanied by bicarbonate efflux.

APA, Harvard, Vancouver, ISO, and other styles

14

Troyanovskaya, Marta, Gomathi Jayaraman, Lijun Song, and Dennis P. Healy. "Aminopeptidase-A. I. cDNA cloning and expression and localization in rat tissues." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 278, no. 2 (February 1, 2000): R413—R424. http://dx.doi.org/10.1152/ajpregu.2000.278.2.r413.

Full text

Abstract:

Aminopeptidase-A (APA) is an ectoenzyme that selectively hydrolyzes acidic residues from the amino terminus of oligopeptides, including biologically active [Asp1]ANG II and [Asp1]CCK-8. We sought to characterize rat APA by cDNA cloning and expression and to determine its tissue distribution by in situ hybridization and immunohistochemistry. Sequence analysis of overlapping cDNA clones isolated from rat kidney cDNA libraries indicated that the full-length cDNA encoded a 945-amino acid protein with a predicted molecular mass of 108 kDa; the size was confirmed by in vitro translation of a full-length cDNA construct. Transient transfection of the full-length cDNA construct in mammalian cells yielded a protein ∼140 kDa in size, a size that agrees with the immunoblots of APA from rat tissue and is consistent with APA being known as a glycosylated protein. Tissue APA activity and mRNA expression were highest in the kidney and ileum. Localization of APA by in situ hybridization and immunohistochemistry indicated that, with the exception of the kidney and ileum, where APA was localized to the luminal brush border of proximal tubules and enterocytes, respectively, APA was associated with either capillaries or the lining of sinusoids. Areas known to be physiological targets for ANG II, including glomeruli, the zona glomerulosa, and anterior pituitary, had high levels of APA. The localization pattern suggests that APA may subserve multiple functions, i.e., a generalized role in peptide scavenging and perhaps a more specific role in metabolism of circulating or locally produced ANG II or CCK-8.

APA, Harvard, Vancouver, ISO, and other styles

15

Howard Nielsen, Jeffery Jay, Stewart A. Low, and Philip S. Low. "3505 Fracture Targeted Parathyroid Hormone Agonist As An Effective Pharmaceutical For Bone Repair in Mouse and Canine Models." Journal of Clinical and Translational Science 3, s1 (March 2019): 105–6. http://dx.doi.org/10.1017/cts.2019.241.

Full text

Abstract:

OBJECTIVES/SPECIFIC AIMS: The primary objective of this study was to evaluate the performance of a bone fracture targeted systemically administrable bone anabolic as a potential therapeutic for bone fracture repair. Currently all bone fracture repair therapeutic require local administration during surgery. However, the population that need the most assistance in repair bone fractures are not eligible for surgery. So, it was our goal to design an inject-able therapeutic to assist in bone fracture repair to reduce the invasiveness. The injectable nature of it allows for repair administration of the bone anabolic and for therapeutic effect throughout the entire bone fracture healing process. Targeting it to the bone fracture site reduces the toxicity and increases the efficacy. METHODS/STUDY POPULATION: METHODS To achieve the above objective, a bone mineral-(hydroxyapatite-) targeting oligopeptide was conjugated to the non-signaling end of an engineered parathyroid hormone related protein fragment 1-46 with substitutions at Glu22,25, Leu23,28,31, Aib29, Lys26,30 (ePTHrP). The negatively charged oligopeptide has been shown to target raw hydroxyapatite with remarkable specificity, while the attached PTHrP has been demonstrated to induce sustained and accelerated bone growth under control of endogenous morphogenic regulatory factors. The conjugate’s specificity arises from the fact that raw hydroxyapatite is only exposed whenever a bone is fractured, surgically cut, grafted, or induced to undergo accelerated remodeling. The hydroxyapatite-targeted conjugate can therefore be administered systemically (i.e. without invasive surgery or localized injection) and still accumulate on the exposed hydroxyapatite at the fracture site where it accelerates the healing process Murine in vivo experiments were conducted on female Swiss Webster mice (10 per group). Femoral fractures were induced with a 3-point bending device and stabilized. Mice were dosed with 3 nmol/kg/d of targeted-ePTHrP, non-conjugated (free) ePTHrP, or saline. Following a 4-week study, fracture callus densities were measured using microCT. Canine in vivo experiments were conducted on 1-year-old male beagles. Beagles underwent a 10 mm bilateral ulnar ostectomy. Two dogs in the treatment group and Three dogs in the control group were dosed daily with either targeted-ePTHrP 0.5nmol/kg/d or saline respectively. Dogs were x-rayed weekly for the first 6 weeks and then every other week thereafter. One tailed ANOVA followed by Dunnett’s post-hoc test was used to establish significance. All animal experiments were conducted as described in approved IACUC protocols. P<0.05 was considered significant. RESULTS/ANTICIPATED RESULTS: RESULTS SECTION: In the murine studies we observed a marked increase in fracture callus size and a 2-fold increase in bone deposition was observed in the targeted-ePTHrP group over the saline group (P<0.01). A significant doubling in bone density was also observed. Targeted-ePTHrP group fractured femurs were able to achieve their pre-fracture strength as early as 3 weeks compared to 9 weeks in the saline mice representing a 66% reduction in healing time. In the canine studies, we observe a significantly higher closure of the ostectomy gap than saline controls (P<0.05). In addition, no significant differences in weight are observed in the treatment vs. saline controls. No significant difference between the control group and treatment groups was found in a histological investigation of the organs. DISCUSSION/SIGNIFICANCE OF IMPACT: DISCUSSION: Although attempts have been made in developing a systemically administered fracture therapeutic for fracture repair, i.e. teriparatide, to date, no such anabolics have been approved for this use. In these studies there is evidence that anabolic activity was occurring at the fracture site, but at a level that did not meet FDA required end-points.2 It is plausible that if sufficient drug were to be delivered to a fracture site then improved fracture repair would be possible. In previous studies, we demonstrated fracture specific accumulation bone anabolics can be achieved by modifying the drug with acidic oligopeptides.3 Here, by modifying a safe, clinically proven, parathyroid hormone receptor agonist with an acidic oligopeptide we observe improved bone deposition and strength in mice. Furthermore, when administered to canine critical sized defect ostectomies, a more relevant and difficult model, we observe improved ostectomy closure. CLINICAL RELEVANCE:: The ability to accelerate bone fracture repair is a fundamental need that has not been addressed by conventional methods. By targeting bone anabolic agents to bone fractures, we can deliver sufficient concentrations of anabolic agent to the fracture site to accelerate healing, thus avoiding surgery and any ectopic bone growth associated with locally-applied bone anabolic agents.

APA, Harvard, Vancouver, ISO, and other styles

16

NAKAMURA, Ko, Kunihiko HIGASHIURA, and Kazuharu IENAGA. "Simple peptides. IV. B/E linked scan sputtered ion mass spectrometry(SIMS) technique useful to distinguish the mode of linkage of an N-terminal acidic .ALPHA.-amino acid in oligopeptides." CHEMICAL & PHARMACEUTICAL BULLETIN 37, no. 1 (1989): 73–76. http://dx.doi.org/10.1248/cpb.37.73.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Juillard, Vincent, Alain Guillot, Dominique Le Bars, and Jean-Claude Gripon. "Specificity of Milk Peptide Utilization byLactococcus lactis." Applied and Environmental Microbiology 64, no. 4 (April 1, 1998): 1230–36. http://dx.doi.org/10.1128/aem.64.4.1230-1236.1998.

Full text

Abstract:

ABSTRACT To study the substrate specificity of the oligopeptide transport system of Lactococcus lactis for its natural substrates, the growth of L. lactis MG1363 was studied in a chemically defined medium containing milk peptides or a tryptic digest of αs2-casein as the source of amino acids. Peptides were separated into acidic, neutral, and basic pools by solid-phase extraction or by cation-exchange liquid chromatography. Their ability to sustain growth and the time course of their utilization demonstrated the preferential use of hydrophobic basic peptides with molecular masses ranging between 600 and 1,100 Da by L. lactis MG1363 and the inability to use large, acidic peptides. These peptide utilization preferences reflect the substrate specificity of the oligopeptide transport system of the strain, since no significant cell lysis was inferred. Considering the free amino acid content of milk and these findings on peptide utilization, it was demonstrated that the cessation of growth of L. lactis MG1363 in milk was due to deprivation of leucine and methionine.

APA, Harvard, Vancouver, ISO, and other styles

18

Takahashi, Tatsuo, Koichi Yokogawa, Naoki Sakura, Masaaki Nomura, Shinjiro Kobayashi, and Ken-ichi Miyamoto. "Bone-Targeting of Quinolones Conjugated with an Acidic Oligopeptide." Pharmaceutical Research 25, no. 12 (July 29, 2008): 2881–88. http://dx.doi.org/10.1007/s11095-008-9605-4.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Stepniak, Dariusz, Liesbeth Spaenij-Dekking, Cristina Mitea, Martine Moester, Arnoud de Ru, Renee Baak-Pablo, Peter van Veelen, Luppo Edens, and Frits Koning. "Highly efficient gluten degradation with a newly identified prolyl endoprotease: implications for celiac disease." American Journal of Physiology-Gastrointestinal and Liver Physiology 291, no. 4 (October 2006): G621—G629. http://dx.doi.org/10.1152/ajpgi.00034.2006.

Full text

Abstract:

Celiac disease is a T cell-driven intolerance to wheat gluten. The gluten-derived T cell epitopes are proline-rich and thereby highly resistant to proteolytic degradation within the gastrointestinal tract. Oral supplementation with prolyl oligopeptidases has therefore been proposed as a potential therapeutic approach. The enzymes studied, however, have limitations as they are irreversibly inactivated by pepsin and acidic pH, both present in the stomach. As a consequence, these enzymes will fail to degrade gluten before it reaches the small intestine, the site where gluten induces inflammatory T cell responses that lead to celiac disease. We have now determined the usefulness of a newly identified prolyl endoprotease from Aspergillus niger for this purpose. Gluten and its peptic/tryptic digest were treated with prolyl endoprotease, and the destruction of the T cell epitopes was tested using mass spectrometry, T cell proliferation assays, ELISA, reverse-phase HPLC, SDS-PAGE, and Western blotting. We observed that the A. niger prolyl endoprotease works optimally at 4–5 pH, remains stable at 2 pH, and is completely resistant to digestion with pepsin. Moreover, the A. niger-derived enzyme efficiently degraded all tested T cell stimulatory peptides as well as intact gluten molecules. On average, the endoprotease from A. niger degraded gluten peptides 60 times faster than a prolyl oligopeptidase. Together these results indicate that the enzyme from A. niger efficiently degrades gluten proteins. Future studies are required to determine if the prolyl endoprotease can be used as an oral supplement to reduce gluten intake in patients.

APA, Harvard, Vancouver, ISO, and other styles

20

Lee, Ni-Chung, Darin J. Falk, Barry J. Byrne, Thomas J. Conlon, Nathalie Clement, Stacy Porvasnik, Marda L. Jorgensen, et al. "An acidic oligopeptide displayed on AAV2 improves axial muscle tropism after systemic delivery." Genetic Vaccines and Therapy 10, no. 1 (2012): 3. http://dx.doi.org/10.1186/1479-0556-10-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Sekido, Tohru, Naoki Sakura, Yasuhiko Higashi, Kazuhiro Miya, Youko Nitta, Masaaki Nomura, Hiroyuki Sawanishi, et al. "Novel Drug Delivery System to Bone Using Acidic Oligopeptide: Pharmacokinetic Characteristics and Pharmacological Potential." Journal of Drug Targeting 9, no. 2 (January 2001): 111–21. http://dx.doi.org/10.3109/10611860108997922.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Miyamoto, Kenichi, Tatsuo Takahashi-Nishioka, Koichi Yokogawa, Shunji Tomatsu, Masaaki Nomura, and Shinjiro Kobayashi. "Targeted Drug Delivery to Bone: Pharmacokinetic and Pharmacological Properties of Acidic Oligopeptide-Tagged Drugs." Current Drug Discovery Technologies 5, no. 1 (March 1, 2008): 39–48. http://dx.doi.org/10.2174/157016308783769405.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Polgár, L. "Effects of ionic strength on the catalysis and stability of prolyl oligopeptidase." Biochemical Journal 312, no. 1 (November 15, 1995): 267–71. http://dx.doi.org/10.1042/bj3120267.

Full text

Abstract:

Prolyl oligopeptidase is the prototype of a new serine protease family, unrelated to trypsin and subtilisin. In contrast with these proteases, prolyl oligopeptidase is remarkably sensitive to ionic strength, being more active in the presence of high concentrations of salt. The enzyme has two catalytic forms, which interconvert with changing pH. To reveal the structural bases of these phenomena, the effects of 0.5 M NaCl on the stability of the enzyme were investigated by studying its denaturation as a function of pH, temperature, and urea concentration. The three independent methods have unequivocally demonstrated that denaturation of the enzyme is promoted in the presence of NaCl. Furthermore, destabilization of the low-pH form by urea is more significant than that of the high-pH form. Examination of the fluorescence emission spectra of various denatured forms indicates that the enzyme is not fully unfolded in 8 M urea, nor at acidic pH. The tryptophan residues in the acid-denatured state are mainly buried. The results are interpreted in terms of the decay of the protective water shell at the higher ionic strength. The higher enthalpy and entropy of activation for heat denaturation provide further evidence that a more ordered water structure stabilizes the protein in the absence of salt. The biphasic kinetics obtained with denaturation by heat and urea suggest that the enzyme has two domains of different stabilities.

APA, Harvard, Vancouver, ISO, and other styles

24

Nishioka, Tatsuo, Shunji Tomatsu, Monica A. Gutierrez, Ken-ichi Miyamoto, Georgeta G. Trandafirescu, Patricia L. C. Lopez, Jeffrey H. Grubb, et al. "Enhancement of drug delivery to bone: Characterization of human tissue-nonspecific alkaline phosphatase tagged with an acidic oligopeptide." Molecular Genetics and Metabolism 88, no. 3 (July 2006): 244–55. http://dx.doi.org/10.1016/j.ymgme.2006.02.012.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Yokogawa, Koichi, Kazuhiro Miya, Tohru Sekido, Yasuhiko Higashi, Masaaki Nomura, Ryuichi Fujisawa, Keiko Morito, et al. "Selective Delivery of Estradiol to Bone by Aspartic Acid Oligopeptide and Its Effects on Ovariectomized Mice." Endocrinology 142, no. 3 (March 1, 2001): 1228–33. http://dx.doi.org/10.1210/endo.142.3.8024.

Full text

Abstract:

Abstract We have developed a novel osteotropic prodrug of estradiol (E2) conjugated with l-Asp-hexapeptide (E2·3D6), which has very low affinity for estrogen receptors, and in this study, we examined its pharmacokinetic behavior and pharmacological potential. After a single iv injection of E2·3D6 to mice, the half-time for elimination from plasma was about 100 min; however, E2 was selectively delivered to the bone and eliminated very slowly, declining to the endogenous level at about 7 days. After a single iv injection of E2, the half-time in plasma was about 70 min, whereas E2 was highly distributed to the uterus, and the bone concentration of E2 was only slightly increased at 6 h. When E2 (0.37 μmol/kg, sc, every third day) or E2·3D6 (0.11 to 1.1 μmol/kg, sc, every seventh day) was administered to OVX mice for 4 weeks, E2 increased the bone mineral density (BMD) together with weights of liver and uterus, whereas E2·3D6 increased only the BMD, in a dose-dependent manner. E2·3D6 enhanced the expression of messenger RNAs of bone matrix proteins (osteopontin, bone sialoprotein, type I collagen α) of OVX mice at 4 h after administration, but E2 did very slightly. These results indicate that the E2 prodrug was delivered to the bone, where it gradually released E2, thereby ameliorating bone loss. This acidic oligopeptide appears to be a good candidate for selective drug delivery to bone.

APA, Harvard, Vancouver, ISO, and other styles

26

Ray, Kallol, Christina S. Hines, Jerry Coll-Rodriguez, and David W. Rodgers. "Crystal Structure of Human Thimet Oligopeptidase Provides Insight into Substrate Recognition, Regulation, and Localization." Journal of Biological Chemistry 279, no. 19 (March 3, 2004): 20480–89. http://dx.doi.org/10.1074/jbc.m400795200.

Full text

Abstract:

Thimet oligopeptidase (TOP) is a zinc metallopeptidase that metabolizes a number of bioactive peptides and degrades peptides released by the proteasome, limiting antigenic presentation by MHC class I molecules. We present the crystal structure of human TOP at 2.0-Å resolution. The active site is located at the base of a deep channel that runs the length of the elongated molecule, an overall fold first seen in the closely related metallopeptidase neurolysin. Comparison of the two related structures indicates hinge-like flexibility and identifies elements near one end of the channel that adopt different conformations. Relatively few of the sequence differences between TOP and neurolysin map to the proposed substrate-binding site, and four of these variable residues may account for differences in substrate specificity. In addition, a loop segment (residues 599-611) in TOP differs in conformation and degree of order from the corresponding neurolysin loop, suggesting it may also play a role in activity differences. Cysteines thought to mediate covalent oligomerization of rat TOP, which can inactivate the enzyme, are found to be surface-accessible in the human enzyme, and additional cysteines (residues 321,350, and 644) may also mediate multimerization in the human homolog. Disorder in the N terminus of TOP indicates it may be involved in subcellular localization, but a potential nuclear import element is found to be part of a helix and, therefore, unlikely to be involved in transport. A large acidic patch on the surface could potentially mediate a protein-protein interaction, possibly through formation of a covalent linkage.

APA, Harvard, Vancouver, ISO, and other styles

27

Zhirnov, O. P., T. E. Konakova, W. Garten, and H. D. Klenk. "Caspase-Dependent N-Terminal Cleavage of Influenza Virus Nucleocapsid Protein in Infected Cells." Journal of Virology 73, no. 12 (December 1, 1999): 10158–63. http://dx.doi.org/10.1128/jvi.73.12.10158-10163.1999.

Full text

Abstract:

ABSTRACT The nucleocapsid protein (NP) (56 kDa) of human influenza A viruses is cleaved in infected cells into a 53-kDa form. Likewise, influenza B virus NP (64 kDa) is cleaved into a 55-kDa protein with a 62-kDa intermediate (O. P. Zhirnov and A. G. Bukrinskaya, Virology 109:174–179, 1981). We show now that an antibody specific for the N terminus of influenza A virus NP reacted with the uncleaved 56-kDa form but not with the truncated NP53 form, indicating the removal of a 3-kDa peptide from the N terminus. Amino acid sequencing revealed the cleavage sites ETD16*G for A/Aichi/68 NP and sites DID7*G and EAD61*V for B/Hong Kong/72 NP. With D at position −1, acidic amino acids at position −3, and aliphatic ones at positions −2 and +1, the NP cleavage sites show a recognition motif typical for caspases, key enzymes of apoptosis. These caspase cleavage sites demonstrated evolutionary stability and were retained in NPs of all human influenza A and B viruses. NP of avian influenza viruses, which is not cleaved in infected cells, contains G instead of D at position 16. Oligopeptide DEVD derivatives, specific caspase inhibitors, were shown to prevent the intracellular cleavage of NP. All three events, the NP cleavage, the increase of caspase activity, and the development of apoptosis, coincide in cells infected with human influenza A and B viruses. The data suggest that intracellular cleavage of NP is exerted by host caspases and is associated with the development of apoptosis at the late stages of infection.

APA, Harvard, Vancouver, ISO, and other styles

28

Rabinovich, Gabriel A., María M. Iglesias, Nidia M. Modesti, Leonardo F. Castagna, Carlota Wolfenstein-Todel, Clelia M. Riera, and Claudia E. Sotomayor. "Activated Rat Macrophages Produce a Galectin-1-Like Protein That Induces Apoptosis of T Cells: Biochemical and Functional Characterization." Journal of Immunology 160, no. 10 (May 15, 1998): 4831–40. http://dx.doi.org/10.4049/jimmunol.160.10.4831.

Full text

Abstract:

Abstract Galectins, a family of closely related β-galactoside-binding proteins, show specific immunomodulatory properties. We have recently identified the presence of a galectin-like protein in rat peritoneal macrophages by means of a cross-reactivity with a polyclonal Ab raised against a galectin purified from adult chicken liver. Galectin expression was up-regulated in inflammatory and activated macrophages, revealing a significant increase in phorbol ester- and formylmethionine oligopeptide-treated cells. In an attempt to further explore its functional significance, rat macrophage galectin was purified from activated macrophages by a single-step affinity chromatography on a lactosyl-Sepharose matrix. The eluted fraction was resolved as a single protein band of ∼15,000 Da by SDS-PAGE that immunoreacted strongly with the anti-chicken galectin serum. Gel filtration studies revealed that the protein behaved like a dimer under native conditions, and saccharides bearing a β-d-galactoside configuration were able to inhibit the hemagglutinating activity displayed by the purified galectin. In agreement with its isoelectric point of ∼4.8, the amino acid analysis showed a definitive acidic pattern. Internal amino acid sequencing of selected peptides obtained by proteolytic cleavage revealed that this carbohydrate-binding protein shares all the absolutely preserved and critical residues found in other members of the mammalian galectin-1 subfamily. Finally, biochemical and ultrastructural evidence, obtained by genomic DNA fragmentation and transmission electron microscopy, are also provided to show its potential implications in the apoptotic program of T cells. This effect was quantified by using the terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end-labeling assay and was found to be associated to the specific carbohydrate-binding properties of galectin.

APA, Harvard, Vancouver, ISO, and other styles

29

Bober, B., J. Bialczyk, and E. Chrapusta-Srebrny. "Effect of abiotic factors on the stability of chosen oligopeptides isolated from the freshwater cyanobacterium Woronichinia naegeliana." International Journal of Environmental Science and Technology, August 24, 2022. http://dx.doi.org/10.1007/s13762-022-04474-4.

Full text

Abstract:

AbstractCyanobacterial blooms have a significant impact on water quality. Implementing appropriate treatment methods to remove cyanobacterial secondary metabolites requires assessing their stability. In contrast to cyanotoxins, the effect of abiotic factors on cyanopeptides has been poorly studied. The present study analysed the impact of pH, temperature, visible and ultraviolet (UV) radiation on the stability of chosen oligopeptides found in a freshwater cyanobacterium Woronichinia naegeliana bloom that frequently appears in drinking water reservoirs worldwide. The tested cyanopeptolin 1081 (CYA-1081) and anabaenopeptin 899 (ANB-899) were relatively stable at room temperature for 12 weeks regardless of pH. However, boiling (100 °C) for one hour affected the partial decomposition of the compounds in a pH-dependent manner; the highest decrease in the initial content of CYA-1081 to 47.0% was recorded at pH 9, while for ANB-899 to 42.4% at pH 3. The tested cyanopeptolin was resistant to visible radiation, but UV radiation in an acidic condition caused its degradation by 32.3%. Treatment of ANB-899 with visible or UV radiation for 3 h caused its partial decomposition with a maximum reduction of 40.4 and 70.8%, respectively, at acidic pH. The presented data provided information on factors affecting the cyanopeptides persistence and may be useful in the search for and development of effective methods of removing cyanobacterial metabolites.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Acidic oligopeptides'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles