Relevant bibliographies by topics / Hexameric protein

Academic literature on the topic 'Hexameric protein'

Author: Grafiati
Published: 10 December 2022
Last updated: 28 January 2023

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

Select a source type:

Contents

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Hexameric protein.'

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.

Journal articles on the topic "Hexameric protein"

1

Jomaa, Ahmad, Jack Iwanczyk, Julie Tran, and Joaquin Ortega. "Characterization of the Autocleavage Process of the Escherichia coli HtrA Protein: Implications for its Physiological Role." Journal of Bacteriology 191, no. 6 (December 19, 2008): 1924–32. http://dx.doi.org/10.1128/jb.01187-08.

Full text
Abstract:
ABSTRACT The Escherichia coli HtrA protein is a periplasmic protease/chaperone that is upregulated under stress conditions. The protease and chaperone activities of HtrA eliminate or refold damaged and unfolded proteins in the bacterial periplasm that are generated upon stress conditions. In the absence of substrates, HtrA oligomerizes into a hexameric cage, but binding of misfolded proteins transforms the hexamers into bigger 12-mer and 24-mer cages that encapsulate the substrates for degradation or refolding. HtrA also undergoes partial degradation as a consequence of self-cleavage of the mature protein, producing short-HtrA protein (s-HtrA). The aim of this study was to examine the physiological role of this self-cleavage process. We found that the only requirement for self-cleavage of HtrA into s-HtrA in vitro was the hydrolysis of protein substrates. In fact, peptides resulting from the hydrolysis of the protein substrates were sufficient to induce autocleavage. However, the continuous presence of full-length substrate delayed the process. In addition, we observed that the hexameric cage structure is required for autocleavage and that s-HtrA accumulates only late in the degradation reaction. These results suggest that self-cleavage occurs when HtrA reassembles back into the resting hexameric structure and peptides resulting from substrate hydrolysis are allosterically stimulating the HtrA proteolytic activity. Our data support a model in which the physiological role of the self-cleavage process is to eliminate the excess of HtrA once the stress conditions cease.
APA, Harvard, Vancouver, ISO, and other styles
2

de Haas, Felix, Jan F. L. van Breemen, Martha M. C. Bijlholt, and Ernst F. J. van Bruggen. "Analysis of Interhexameric Contact Regions in Two Dodecameric Hemocyanins at Subdohain Resolution by Combination of Data from Electron Microscopy, X-Ray Diffraction and Amino-Acid Sequence Studies." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 1 (August 12, 1990): 266–67. http://dx.doi.org/10.1017/s0424820100180082.

Full text
Abstract:
Hemocyanin is a biological macromolecule which occurs freely dissolved in the hemolymph of certain invertebrates. The function of this copper containing protein is the transport of oxygen through the organism. In fulfilling this task hemocyanin has developed a similar mechanism as hemoglobin in binding oxygen reversibly and cooperatively. The hemocyanin of arthropods consists of one or more hexamers of subunits with a molecular weight of approx. 75 000. Depending on the species 3-15 types of monomeric subunits occur, which differ in amino-acid composition and in their oxygen binding properties. Each type of subunit fulfills a specific role in the architecture of that hemocyanin. In nature arthropodan hemocyanin is found as a one-hexameric, two-hexameric (dodecameric), four-hexameric or eight-hexameric molecular assembly depending on the species. In this work we focus on the difference in organization of the hexamers in the dodecamer of two different species i.e. the tarantula Eurypelma californicum (a chelicerate) and the crab Cancer pagurus (a crustacean). Eurypelma hemocyanin is made from 7 different subunits called a - g, whereas Cancer hemocyanin consists of 3 subunit types termed α, β, and γ .By image analysis of electron micrographs of the two-hexameric half hemocyanin molecules from Eurypelma and the two-hexameric whole hemocyanin molecules from Cancer, computer averaged projections of these dodecamers were obtained as shown in fig. 1. They differ clearly in their interhexameric contacts. To analyse this difference in more detail these projections were used as a reference in a simulation procedure.
APA, Harvard, Vancouver, ISO, and other styles
3

Jomaa, Ahmad, Daniela Damjanovic, Vivian Leong, Rodolfo Ghirlando, Jack Iwanczyk, and Joaquin Ortega. "The Inner Cavity of Escherichia coli DegP Protein Is Not Essentialfor Molecular Chaperone and Proteolytic Activity." Journal of Bacteriology 189, no. 3 (November 22, 2006): 706–16. http://dx.doi.org/10.1128/jb.01334-06.

Full text
Abstract:
ABSTRACT The Escherichia coli DegP protein is an essential periplasmic protein for bacterial survival at high temperatures. DegP has the unusual property of working as a chaperone below 28°C, but efficiently degrading unfolded proteins above 28°C. Monomeric DegP contains a protease domain and two PDZ domains. It oligomerizes into a hexameric cage through the staggered association of trimers. The active sites are located in a central cavity that is only accessible laterally, and the 12 PDZ domains act as mobile sidewalls that mediate opening and closing of the gates. As access to the active sites is restricted, DegP is an example of a self-compartmentalized protease. To determine the essential elements of DegP that maintain the integrity of the hexameric cage, we constructed several deletion mutants of DegP that formed trimers rather than hexamers. We found that residues 39 to 78 within the LA loops, as well as the PDZ2 domains are essential for the integrity of the DegP hexamer. In addition, we asked whether an enclosed cavity or cage of specific dimensions is required for the protease and chaperone activities in DegP. Both activities were maintained in the trimeric DegP mutants without an enclosed cavity and in deletion DegP mutants with significantly reduced dimensions of the cage. We conclude that the functional unit for the protease and chaperone activities of DegP is a trimer and that neither a cavity of specific dimensions nor the presence of an enclosed cavity appears to be essential for the protease and chaperone activities of DegP.
APA, Harvard, Vancouver, ISO, and other styles
4

Lu, Jinghua, Terry Du Clos, Carolyn Mold, and Peter Sun. "The structural mechanism of Serum Amyloid A -mediated Secondary amyloid formation (135.34)." Journal of Immunology 184, no. 1_Supplement (April 1, 2010): 135.34. http://dx.doi.org/10.4049/jimmunol.184.supp.135.34.

Full text
Abstract:
Abstract Secondary amyloidosis is a severe complication of many chronic inflammatory diseases, such as rheumatoid arthritis and atherosclerosis, when the C-terminally cleaved fragments of acute phase protein Serum Amyloid A (SAA) are deposited in tissues as amyloid fibrils. The pathologic process of secondary amyloidosis involves a conversion of the structure of native SAA into a predominantly antiparallel β-sheet secondary structure. We have now determined the X-ray structure of SAA in a monomeric and a hexameric form at 2.2Å and 2.7Å resolution, respectively. The hexameric SAA structure revealed a dimeric architecture arranged as two trimers. Strong interactions between the C-terminal loop region and four-helix-bundle core of the SAA monomers create a stable structure to prevent secondary structure refolding during amyloidogenesis. The presence of multimeric forms in human serum was confirmed by size-exclusion experiments. Recombinant monomeric, trimeric and hexameric SAA protein were purified from Escherichia coli and characterized. Binding studies show that the monomeric and trimeric but not the hexameric SAA bind to Toll-like receptor 2 and 4. In line with these experiments, SAA may undergo a transition between hexamers and monomers, which would activate Toll-like receptors to further complicate the chronic inflammation in disease situation.
APA, Harvard, Vancouver, ISO, and other styles
5

Hankins, J. S., H. Denroche, and G. A. Mackie. "Interactions of the RNA-Binding Protein Hfq with cspA mRNA, Encoding the Major Cold Shock Protein." Journal of Bacteriology 192, no. 10 (March 16, 2010): 2482–90. http://dx.doi.org/10.1128/jb.01619-09.

Full text
Abstract:
ABSTRACT CspA, a small protein that is highly induced by cold shock, is encoded by a monocistronic mRNA of 428 nucleotides (nt) whose half-life and abundance are greatly increased following cold shock. We show here that in vitro cspA mRNA can bind multiple copies of Hfq, a hexameric Sm-like protein which promotes a variety of RNA-RNA interactions. Binding of the first Hfq hexamer occurs with an apparent Kd (dissociation constant) of <40 nM; up to seven additional hexamers can bind sequentially at higher concentrations. Known ligands of Hfq, including the small regulatory RNA, RyhB, compete with cspA mRNA. Several experiments suggest that the first binding site to be occupied by Hfq is located at or near the 3′ end of cspA mRNA. The consequences of limited Hfq binding in vitro include nearly total inhibition of RNase E cleavage at a site ∼35 nt from the 3′ end of the mRNA, stimulation of polyadenylation by poly(A) polymerase 1, and subsequent exonucleolytic degradation by polynucleotide phosphorylase. We propose that Hfq may play a facilitating role in the metabolism of cspA mRNA.
APA, Harvard, Vancouver, ISO, and other styles
6

Heinemann, Udo, Yvette Roske, Anup Arumughan, and Erich Wanker. "Remodeling of the AAA+ ATPase p97 by the UBX Adaptor Protein ASPL." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C430. http://dx.doi.org/10.1107/s2053273314095692.

Full text
Abstract:
The hexameric mammalian AAA+ ATPase p97, also known as VCP (valosin-containing protein; CDC48 in yeast), is a very abundant cytosolic protein and serves a wide variety of cellular functions. p97 is a central component in endoplasmic reticulum-associated degradation (ERAD) of proteins where it delivers ubiquitinated ERAD substrates to the proteasome. In addition, cellular roles of p97 in organelle membrane fusion, mitosis, DNA repair and suppression of apoptosis have been described. These different functions are linked to the binding of adaptor proteins to p97. Many of these adaptors contain ubiquitin regulatory X (UBX) domains. ASPL (alveolar soft part sarcoma locus, also known as TUG) was recenty identified as a p97 adaptor protein. As shown by crystal structure analysis, ASPL uses a substantially extended UBX domain for binding to the N domain of p97 where a lariat-like, mostly α-helical extension wraps around one subunit of p97. By this binding ASPL triggers the dissociation of functional p97 hexamers and the formation of p97:ASPL heterotetramers with 2:2 stoichiometry, leading to inactivation of the AAA+ ATPase. The p97-ASPL interaction in the heterotetramer is very tight, but p97 hexamer dissociation and heterotetramer formation may be suppressed by single-site mutations at p97-ASPL interfaces. p97 hexamer dissociation and p97-ASPL heterotetramer formation are linked to reduced ATPase activity of p97, cellular accumulation of ERAD substrates and apoptosis induction. To the best of our knowledge, this is the first time that the structural basis for adaptor protein-induced inactivation by hexamer dissociation of p97 and, indeed, any AAA+ ATPase has been demonstrated. This observation has far reaching implications for AAA+ ATPase-regulated processes.
APA, Harvard, Vancouver, ISO, and other styles
7

Chaudhury, Paushali, Chris van der Does, and Sonja-Verena Albers. "Characterization of the ATPase FlaI of the motor complex of the Pyrococcus furiosus archaellum and its interactions between the ATP-binding protein FlaH." PeerJ 6 (June 18, 2018): e4984. http://dx.doi.org/10.7717/peerj.4984.

Full text
Abstract:
The archaellum, the rotating motility structure of archaea, is best studied in the crenarchaeon Sulfolobus acidocaldarius. To better understand how assembly and rotation of this structure is driven, two ATP-binding proteins, FlaI and FlaH of the motor complex of the archaellum of the euryarchaeon Pyrococcus furiosus, were overexpressed, purified and studied. Contrary to the FlaI ATPase of S. acidocaldarius, which only forms a hexamer after binding of nucleotides, FlaI of P. furiosus formed a hexamer in a nucleotide independent manner. In this hexamer only 2 of the ATP binding sites were available for binding of the fluorescent ATP-analog MANT-ATP, suggesting a twofold symmetry in the hexamer. P. furiosus FlaI showed a 250-fold higher ATPase activity than S. acidocaldarius FlaI. Interaction studies between the isolated N- and C-terminal domains of FlaI showed interactions between the N- and C-terminal domains and strong interactions between the N-terminal domains not previously observed for ATPases involved in archaellum assembly. These interactions played a role in oligomerization and activity, suggesting a conformational state of the hexamer not observed before. Further interaction studies show that the C-terminal domain of PfFlaI interacts with the nucleotide binding protein FlaH. This interaction stimulates the ATPase activity of FlaI optimally at a 1:1 stoichiometry, suggesting that hexameric PfFlaI interacts with hexameric PfFlaH. These data help to further understand the complex interactions that are required to energize the archaellar motor.
APA, Harvard, Vancouver, ISO, and other styles
8

Chen, Zhenguo, Lei Sun, Zhihong Zhang, Andrei Fokine, Victor Padilla-Sanchez, Dorit Hanein, Wen Jiang, Michael G. Rossmann, and Venigalla B. Rao. "Cryo-EM structure of the bacteriophage T4 isometric head at 3.3-Å resolution and its relevance to the assembly of icosahedral viruses." Proceedings of the National Academy of Sciences 114, no. 39 (September 11, 2017): E8184—E8193. http://dx.doi.org/10.1073/pnas.1708483114.

Full text
Abstract:
The 3.3-Å cryo-EM structure of the 860-Å-diameter isometric mutant bacteriophage T4 capsid has been determined. WT T4 has a prolate capsid characterized by triangulation numbers (T numbers) Tend= 13 for end caps and Tmid= 20 for midsection. A mutation in the major capsid protein, gp23, produced T=13 icosahedral capsids. The capsid is stabilized by 660 copies of the outer capsid protein, Soc, which clamp adjacent gp23 hexamers. The occupancies of Soc molecules are proportional to the size of the angle between the planes of adjacent hexameric capsomers. The angle between adjacent hexameric capsomers is greatest around the fivefold vertices, where there is the largest deviation from a planar hexagonal array. Thus, the Soc molecules reinforce the structure where there is the greatest strain in the gp23 hexagonal lattice. Mutations that change the angles between adjacent capsomers affect the positions of the pentameric vertices, resulting in different triangulation numbers in bacteriophage T4. The analysis of the T4 mutant head assembly gives guidance to how other icosahedral viruses reproducibly assemble into capsids with a predetermined T number, although the influence of scaffolding proteins is also important.
APA, Harvard, Vancouver, ISO, and other styles
9

Lin, Qing-Peng, Zeng-Qiang Gao, Zhi Geng, Heng Zhang, and Yu-Hui Dong. "Crystal structure of the putative cytoplasmic protein STM0279 (Hcp2) from Salmonella typhimurium." Acta Crystallographica Section F Structural Biology Communications 73, no. 8 (July 26, 2017): 463–68. http://dx.doi.org/10.1107/s2053230x17010512.

Full text
Abstract:
STM0279 is a putative cytoplasmic protein from Salmonella typhimurium and was recently renamed haemolysin co-regulated protein 2 (Hcp2), with the neighbouring STM0276 being Hcp1. Both of them are encoded by the type VI secretion system (T6SS) of the Salmonella pathogenicity island 6 (SPI-6) locus and have high sequence identity. The Hcp proteins may function as a vital component of the T6SS nanotube and as a transporter and chaperone of diverse effectors from the bacterial T6SS. In this study, the crystal structure and the oligomeric state in solution of Hcp2 from S. typhimurium (StHcp2) were investigated. The crystal structure refined to 3.0 Å resolution showed that the protein is composed of a β-barrel domain with extended loops and can form hexameric rings as observed in known Hcp homologues. Mutation of the extended loop was found to partly destabilize the hexameric conformation into monomers or cause the production of inclusion bodies, suggesting it has an important role in hexameric ring formation.
APA, Harvard, Vancouver, ISO, and other styles
10

Oohora, Koji, Shota Hirayama, Tsuyoshi Mashima, and Takashi Hayashi. "Supramolecular dimerization of a hexameric hemoprotein via multiple pyrene-pyrene interactions." Journal of Porphyrins and Phthalocyanines 24, no. 01n03 (January 2020): 259–67. http://dx.doi.org/10.1142/s1088424619500949.

Full text
Abstract:
Protein assemblies are being investigated as a new-class of biomaterials. A supramolecular assembly of a mutant hexameric tyrosine coordinated hemoprotein (HTHP) modified with a pyrene derivative is described. Cysteine was first introduced as a site-specific reaction point at position V44 which is located at the bottom surface of the cylindrical structure of HTHP. [Formula: see text]-(1-pyrenyl)maleimide was then reacted with the mutant. The modification was confirmed by MALDI-TOF mass spectrometry and UV-vis absorption spectroscopy, indicating that approximately 90% cysteine residues are attached via the pyrene derivative. Size exclusion chromatography (SEC) measurements for pyrene-attached HTHP include a single peak which elutes earlier than the unmodified HTHP. Further investigation by SEC and dynamic light scattering (DLS) measurements indicate the desired size corresponding to the dimer of the hemoprotein hexamers. The multivalent effect of pyrene–pyrene interactions including hydrophobic and [Formula: see text]–[Formula: see text] stacking interactions appears to be responsible for including formation of the stable dimer of the hexamers. Interestingly, the assembly dissociates to the hexamer by removal of heme. In the case of the apo-form of pyrene-attached HTHP, the pyrene moiety appears to be incorporated into the heme pocket because the modification point is located at the adjacent residue of the Tyr45 coordinating to heme in the holo-form of HTHP. Subsequent addition of heme into the apo-form of pyrene-attached HTHP regenerates the dimer of the hexamers. The present study demonstrates a unique heme-dependent system in which HTHP is assembled to form a dimer of hexamers in the presence of heme and disassembled by removal of heme.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Hexameric protein"

1

Valentová, Lucie. "Izolace a stanovení struktur proteinů: hexamerin potemníka Tribolium Castaneum a TmpH fága phi812." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2019. http://www.nusl.cz/ntk/nusl-401898.

Full text
Abstract:
Tato práce se zabývá strukturní studií dvou proteinů: proteinu Tail morphogenetic protein H (TmpH) bakteriofága 812, který napadá Zlatého stafylokoka (Staphylococcus aureus) a hexamerinu z potemníka (Tribolium castaneum). S. aureus je jedním z nejvíce rezistentních patogenů způsobující onemocnění s vysokou morbiditou a mortalitou. Bakteriofág 812 je schopen infikovat a lyzovat 95 % kmenů S. aureus a má potenciální využití ve fágové terapii. Protein TmpH je součástí virionu tohoto fága. V rámci této práce bylo připraveno několik plazmidů nesoucích gen TmpH, které byly použity pro rekombinantní expresi proteinu v buňkách E. coli BL21(DE3). Protein byl vyčištěn afinitní a gelovou chromatografií. Pro čistý protein byly optimalizovány krystalizační podmínky. Hexamerin je nejhojnějším proteinem larev a kukel hmyzu s dokonalou proměnou. V průběhu metamorfózy hexamerin slouží jako zdroj aminokyselin. V rámci této práce byl hexamerin izolován z kukel potemníka T. castaneum. Pro stanovení struktury hexamerinu byly použity dvě metody: rentgenová krystalografie a kryo-elektronová mikroskopie. Byly optimalizovány podmínky pro růst krystalů a vypěstovány krystaly vhodné pro sběr difrakčních dat. Nicméně struktura hexamerinu byla rychleji vyřešena kryo-elektronovou mikroskopií s rozlišením 3.2 . Znalost struktury hexamerinu umožní pochopení jeho funkce v regulaci vývoje hmyzu s dokonalou proměnou.
APA, Harvard, Vancouver, ISO, and other styles
2

Reddy, Gangadasu E. C. V. Sagar. "Storage and utilization of hexamerin proteins in the pitcher plant mosquito, Wyomyia smithii by Gangadasu E.C.V. Sagar Reddy." Click here to access thesis, 2008. http://www.georgiasouthern.edu/etd/archive/fall2008/gangadasu_s_reddy/reddy_gangadasu_e_200808_ms.pdf.

Full text
Abstract:
Thesis (M.S.)--Georgia Southern University, 2008.
"A thesis submitted to the Graduate Faculty of Georgia Southern University in partial fulfillment of the requirements for the degree Master of Science." Directed by William S. Irby. ETD. Includes bibliographical references (p. 42-47) and appendices.
APA, Harvard, Vancouver, ISO, and other styles
3

Xue, Yu Lord Susan T. "Study protein-protein interaction in methyl-directed DNA mismatch repair in E. coli exonuclease I Exo I and DNA helicas II UvrD; A minimal exonuclease domain of WRN forms a hexamer on DNA and possesses both 3'-5' exonuclease and 5'-protruding strand endonuclease activities; Solving the structure of the ligand-binding domain of the pregnane-xenobiotic-receptor with 17[beta] estradiol and T1317 /." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2008. http://dc.lib.unc.edu/u?/etd,2015.

Full text
Abstract:
Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2008.
Title from electronic title page (viewed Feb. 17, 2009). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Chemistry." Discipline: Chemistry; Department/School: Chemistry.
APA, Harvard, Vancouver, ISO, and other styles
4

Chakraborti, Srinjoy. "Therapeutic Antibody Against Neisseria gonorrhoeae Lipooligosaccharide, a Phase-variable Virulence Factor." eScholarship@UMMS, 2017. https://escholarship.umassmed.edu/gsbs_diss/905.

Full text
Abstract:
Neisseria gonorrhoeae (Ng) which causes gonorrhea has become multidrug-resistant, necessitating the development of novel therapeutics and vaccines. mAb 2C7 which targets an epitope within an important virulence factor, the lipooligosaccharide (LOS), is a candidate therapeutic mAb. Ninety-four percent of clinical isolates express the 2C7-epitope which is also a vaccine target. Ng expresses multiple LOS(s) due to phase-variation (pv) of LOS glycosyltransferase (lgt) genes. mAb 2C7 reactivity requires a lactose extension from the LOS core Heptose (Hep) II (i.e. lgtG ‘ON’ [G+]). Pv results in HepI with: two (2-), three (3-), four (4-), or five (5-) hexoses (Hex). How HepI glycans impact Ng infectivity and mAb 2C7 function are unknown and form the bases of this dissertation. Using isogenic mutants, I demonstrate that HepI LOS glycans modulate mAb 2C7 binding. mAb 2C7 causes complement (C’)-dependent bacteriolysis of three (2-Hex/G+, 4-Hex/G+, and 5-Hex/G+) of the HepI mutants in vitro. The 3-Hex/G+ mutant (resistant to C’-dependent bacteriolysis) is killed by neutrophils in the presence of mAb and C’. In mice, 2- and 3-Hex/G+ infections are significantly shorter than 4- and 5-Hex/G+ infections. A chimeric mAb 2C7 that hyperactivates C’, attenuates only 4- and 5-Hex/G+ infections. This study enhances understanding of the role of HepI LOS pv in gonococcal infections and shows that longer HepI glycans are necessary for prolonged infections in vivo. This is the first study that predicts in vitro efficacy of mAb 2C7 against all four targetable HepI glycans thereby strengthening the rationale for development of 2C7-epitope based vaccines and therapeutics.
APA, Harvard, Vancouver, ISO, and other styles
5

Chakraborti, Srinjoy. "Therapeutic Antibody Against Neisseria gonorrhoeae Lipooligosaccharide, a Phase-variable Virulence Factor." eScholarship@UMMS, 2005. http://escholarship.umassmed.edu/gsbs_diss/905.

Full text
Abstract:
Neisseria gonorrhoeae (Ng) which causes gonorrhea has become multidrug-resistant, necessitating the development of novel therapeutics and vaccines. mAb 2C7 which targets an epitope within an important virulence factor, the lipooligosaccharide (LOS), is a candidate therapeutic mAb. Ninety-four percent of clinical isolates express the 2C7-epitope which is also a vaccine target. Ng expresses multiple LOS(s) due to phase-variation (pv) of LOS glycosyltransferase (lgt) genes. mAb 2C7 reactivity requires a lactose extension from the LOS core Heptose (Hep) II (i.e. lgtG ‘ON’ [G+]). Pv results in HepI with: two (2-), three (3-), four (4-), or five (5-) hexoses (Hex). How HepI glycans impact Ng infectivity and mAb 2C7 function are unknown and form the bases of this dissertation. Using isogenic mutants, I demonstrate that HepI LOS glycans modulate mAb 2C7 binding. mAb 2C7 causes complement (C’)-dependent bacteriolysis of three (2-Hex/G+, 4-Hex/G+, and 5-Hex/G+) of the HepI mutants in vitro. The 3-Hex/G+ mutant (resistant to C’-dependent bacteriolysis) is killed by neutrophils in the presence of mAb and C’. In mice, 2- and 3-Hex/G+ infections are significantly shorter than 4- and 5-Hex/G+ infections. A chimeric mAb 2C7 that hyperactivates C’, attenuates only 4- and 5-Hex/G+ infections. This study enhances understanding of the role of HepI LOS pv in gonococcal infections and shows that longer HepI glycans are necessary for prolonged infections in vivo. This is the first study that predicts in vitro efficacy of mAb 2C7 against all four targetable HepI glycans thereby strengthening the rationale for development of 2C7-epitope based vaccines and therapeutics.
APA, Harvard, Vancouver, ISO, and other styles
6

Nagamanju, P. "Hexamerins, their gene and binding protein in rice moth, corcyra cephalonica." Thesis, 2003. http://hdl.handle.net/2009/883.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Palivec, Vladimír. "Počítačové modelování interakcí iont ů s proteiny: Allosterický efekt iont ů a fenolických ligand ů na strukturu insulinového hexameru." Master's thesis, 2016. http://www.nusl.cz/ntk/nusl-344126.

Full text
Abstract:
Title: Computer modeling of ion protein interactions: Allosteric effects of phenolic ligands and ions on insulin hexamer structure Author: Vladimír Palivec Department: Department of Physical and Macromolecular Chemistry Faculty of Science UK Advisor: prof. RNDr. Pavel Jungwirth, DSc., IOCB AS CR, v.v.i. Advisor's email address: pavel.jungwirth@uochb.cas.cz Abstract: Insulin hexamer is an allosteric protein capable of undergoing conformational changes between three states: T6, T3R3, and R6. Transitions between them, as well as the formation of insulin hexamers, are mediated through binding of phenolic ligands or ions. This thesis presents a molecular dynamics study of allosteric behavior of insulin using empirical force fields. Two effects are closely inspected - cation (Zn2+ , Ca2+ , K+ , and Na+ ) binding to the insulin hexamers and a possible binding of two neurotransmitters - dopamine and serotonin to the phenolic pocket. The results show that high charge density cations (Zn2+ and Ca2+ ) are mostly localized in the B13 glutamate cavity, slow- down diffusion, while preventing other cations from entering. In contrast, low charge density cations (Na+ and K+ ) do not have this effect. Concerning neurotransmitters, dopamine does not bind to the phenolic pocket whereas serotonin binds in a similar way like...
APA, Harvard, Vancouver, ISO, and other styles
8

Pantakani, Dasaradha Venkata Krishna. "Functional Characterization of Hereditary Spastic Paraplegia Proteins Spastin and ZFYVE27." Doctoral thesis, 2009. http://hdl.handle.net/11858/00-1735-0000-0006-B685-A.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Hexameric protein"

1

Crampton, Donald J., and Charles C. Richardson. "Bacteriophage T7 gene 4 protein: A hexameric DNA helicase." In Energy Coupling and Molecular Motors, 277–302. Elsevier, 2003. http://dx.doi.org/10.1016/s1874-6047(04)80007-6.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Itsathitphaisarn, Ornchuma, Richard A. Wing, William K. Eliason, Jimin Wang, and Thomas A. Steitz. "The Hexameric Helicase DnaB Adopts a Nonplanar Conformation during Translocation." In Structural Insights into Gene Expression and Protein Synthesis, 365–75. WORLD SCIENTIFIC, 2020. http://dx.doi.org/10.1142/9789811215865_0042.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Silva, Jerson L., and Andrea T. Da Poian. "Pressure and Cold Denaturation of Proteins, Protein-DNA Complexes, and Viruses." In High Pressure Effects in Molecular Biophysics and Enzymology. Oxford University Press, 1996. http://dx.doi.org/10.1093/oso/9780195097221.003.0013.

Full text
Abstract:
The application of hydrostatic pressure provides a means of appraising interprotein and intraprotein interactions isothermally and makes it possible to sample partially folded conformations. A number of proteins exhibit cold denaturation and cold dissociation. We have used the combined effects of pressure and low temperature to promote dissociation or denaturation of single-chain proteins, oligomers, protein-DNA complexes, and viruses. In this article, we summarize results that have biological relevance. The dissociation and denaturation of the hexameric protein, allophycocyanin, are accomplished only when the temperature is decreased to —10 °C, indicating the entropic character of the folding and association reaction. The folding and dimerization of Arc repressor in the temperature range of 0—20 °C is also favored by a large positive entropy that counteracts an unfavorable positive enthalpy. On binding operator DNA, Arc repressor becomes extremely stable against denaturation. However, the Arc repressor-operator DNA complex is cold denatured at subzero temperatures under pressure. The entropy increases greatly when Arc repressor binds tightly to its operator sequence but not to a nonspecific sequence. The dissociation and denaturation of icosahedral viruses by pressure and low temperature also have been studied. The procapsid shells of bacteriophage P22 only dissociate by pressure at temperatures below 0 °C. On the other hand, the monomeric coat protein is very unstable toward pressure. Cowpea mosaic virus (CPMV) dissociates only in the presence of 1.0 M urea, at 2.5 kbar when the temperature is decreased to — 15°C. At temperatures close to — 20 °C, partial denaturation is obtained even in the absence of urea. The assembly of CPMV is related to large and positive variations or enthalpy and entropy, making the assembly of ribonucleoprotein components an entropy-driven process. We conclude that protein folding, protein association, and protein-DNA recognition seem to need positive entropy to occur. We are facing a puzzle in which a final, apparently more ordered state is achieved, a state that paradoxically has more entropy. In the last 20 years, several studies have described the cold denaturation of proteins (Brandts, 1964; Sturtevant, 1977; Privalov et al., 1986; Griko et al., 1988; Chen & Schellman, 1989, and as reviewed in Privalov, 1990). However, unlike thermal denaturation, cold denaturation is not well understood.
APA, Harvard, Vancouver, ISO, and other styles
4

Dunn, Michael F., Richard Palmieri, Niels C. Kaarsholm, Melinda Roy, Robert W. K. Lee, Zbignew Dauter, Christopher Hill, and Guy G. Dodson. "THE 2-ZINC INSULIN HEXAMER IS A CALCIUM-BINDING PROTEIN." In Calcium-Binding Proteins in Health and Disease, 372–83. Elsevier, 1987. http://dx.doi.org/10.1016/b978-0-12-521040-9.50062-0.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Roy, Melinda, Robert Lee, and Michael F. Dunn. "1H FT NMR STUDIES OF THE Co3+-SUBSTITUTED HEXAMER: CHARACTERIZATION OF METAL ION BINDING TO THE GLU(B13) SITE." In Calcium-Binding Proteins in Health and Disease, 424–26. Elsevier, 1987. http://dx.doi.org/10.1016/b978-0-12-521040-9.50076-0.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Hexameric protein"

1

Stewart, Ross A., Natalie Tigue, Samantha Ireland, James Hair, Lisa Bamber, Michael Oberst, Rebecca Leyland, et al. "Abstract 561: MEDI1873: A novel hexameric GITRL fusion protein with potent agonsitic and immunomodulatory activities in preclinical systems." In Proceedings: AACR 107th Annual Meeting 2016; April 16-20, 2016; New Orleans, LA. American Association for Cancer Research, 2016. http://dx.doi.org/10.1158/1538-7445.am2016-561.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Andrieux, A., M. H. Charon, G. Hudry-Clergeon, and G. Marguerie. "FIBRINOGEN SEQUENCES INTERACTING WITH PLATELET GPIIbIIIa." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643519.

Full text
Abstract:
Fibrinogen (Fg), fibronectin (Fn) and von Willebrand factor (vWF), interact with GPIIbllla on AD? stimulated platelets, and a common mechanism has been postulated for the binding of these adhesive proteins. Fg, Fn and vWF contain the tripeptide Arg-Gly-Asp and synthetic analogues to this sequence inhibit their interaction with platelet and their concomitant adhesive reactions. On the other hand, sequences corresponding to the Fg γ chain inhibit the binding of Fg, Fn and vWF to platelet and may also represent a potential recognition site. This raises the possibility that the γ chain sequence and Arg-Gly-Asp interact with the same site or represent primary and secondary sites for the Fg molecule. Within this context, the capacity of these sequences to interact with GPIIbllla and to block fibrinogen binding were compared. The smallest γ chain sequence that was active in inhibiting this reaction was the hexamer Lys-Gln-Ala-Gly-Asp-Val corresponding to the last six amino acid residues at the C-terminus of the γ chain. In parallel, peptides with the structure Arg-Gly-Asp-X were synthesized and tested in vitro. The activity of these peptides was dependent upon the hydrophobicity of the amino acid residue at position X. Arg-GLy-Asp-Phe corresponding to the sequence at position 95-98 in the Fg Aα chain was 5 to 10 times more active than Arg-GLy-Asp-Ser, present at position 572-575 in the Aα chain, and was 10 to 20 times more active than the γ chain hexamer. Both the Aα chain and γ chain sequences however, inhibited Fg binding by greater than 90%. When the γ chain sequence and the Arg-Gly-Asp-X sequence were coupled to Sepharose, GPIIbIIIa interacted with these sequences and was eluted from each column by either of the peptides. Finally direct binding experiments indicated that Arg-Gly-Asp-X and γ chain sequences are competitive antagonists. These results suggest that both sequences interact with the same site on GPIIbIIIa and comparison of the hydrophilicity of these peptides suggests that the binding domain on GPIIbIIIa exhibits hydrophobic properties.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Hexameric protein' for particular source types:
Journal articles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography