1
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Zenere G, Wu C, Midkiff CC, Johnson NM, Grice CP, Wimley WC, Kaur A, Braun SE. Extracellular domain, hinge, and transmembrane determinants affecting surface CD4 expression of a novel anti-HIV chimeric antigen receptor (CAR) construct. PLoS One 2024; 19:e0293990. [PMID: 39133676 PMCID: PMC11318886 DOI: 10.1371/journal.pone.0293990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 07/03/2024] [Indexed: 08/15/2024] Open
Abstract
Chimeric antigen receptor (CAR)-T cells have demonstrated clinical potential, but current receptors still need improvements to be successful against chronic HIV infection. In this study, we address some requirements of CAR motifs for strong surface expression of a novel anti-HIV CAR by evaluating important elements in the extracellular, hinge, and transmembrane (TM) domains. When combining a truncated CD4 extracellular domain and CD8α hinge/TM, the novel CAR did not express extracellularly but was detectable intracellularly. By shortening the CD8α hinge, CD4-CAR surface expression was partially recovered and addition of the LYC motif at the end of the CD8α TM fully recovered both intracellular and extracellular CAR expression. Mutation of LYC to TTA or TTC showed severe abrogation of CAR expression by flow cytometry and confocal microscopy. Additionally, we determined that CD4-CAR surface expression could be maximized by the removal of FQKAS motif at the junction of the extracellular domain and the hinge region. CD4-CAR surface expression also resulted in cytotoxic CAR T cell killing of HIV Env+ target cells. In this study, we identified elements that are crucial for optimal CAR surface expression, highlighting the need for structural analysis studies to establish fundamental guidelines of CAR designs.
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Affiliation(s)
- Giorgio Zenere
- Tulane National Primate Research Center, Tulane University School of Medicine, Covington, Louisiana, United States of America
- BioMedical Sciences Program, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Chengxiang Wu
- Tulane National Primate Research Center, Tulane University School of Medicine, Covington, Louisiana, United States of America
| | - Cecily C. Midkiff
- Tulane National Primate Research Center, Tulane University School of Medicine, Covington, Louisiana, United States of America
| | - Nathan M. Johnson
- Tulane National Primate Research Center, Tulane University School of Medicine, Covington, Louisiana, United States of America
- BioMedical Sciences Program, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Christopher P. Grice
- Tulane National Primate Research Center, Tulane University School of Medicine, Covington, Louisiana, United States of America
- BioMedical Sciences Program, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - William C. Wimley
- Department of BioChemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Amitinder Kaur
- Tulane National Primate Research Center, Tulane University School of Medicine, Covington, Louisiana, United States of America
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
| | - Stephen E. Braun
- Tulane National Primate Research Center, Tulane University School of Medicine, Covington, Louisiana, United States of America
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana, United States of America
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2
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Philips EA, Liu J, Kvalvaag A, Mørch AM, Tocheva AS, Ng C, Liang H, Ahearn IM, Pan R, Luo CC, Leithner A, Qin Z, Zhou Y, Garcia-España A, Mor A, Littman DR, Dustin ML, Wang J, Kong XP. Transmembrane domain-driven PD-1 dimers mediate T cell inhibition. Sci Immunol 2024; 9:eade6256. [PMID: 38457513 PMCID: PMC11166110 DOI: 10.1126/sciimmunol.ade6256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 02/15/2024] [Indexed: 03/10/2024]
Abstract
Programmed cell death-1 (PD-1) is a potent immune checkpoint receptor on T lymphocytes. Upon engagement by its ligands, PD-L1 or PD-L2, PD-1 inhibits T cell activation and can promote immune tolerance. Antagonism of PD-1 signaling has proven effective in cancer immunotherapy, and conversely, agonists of the receptor may have a role in treating autoimmune disease. Some immune receptors function as dimers, but PD-1 has been considered monomeric. Here, we show that PD-1 and its ligands form dimers as a consequence of transmembrane domain interactions and that propensity for dimerization correlates with the ability of PD-1 to inhibit immune responses, antitumor immunity, cytotoxic T cell function, and autoimmune tissue destruction. These observations contribute to our understanding of the PD-1 axis and how it can potentially be manipulated for improved treatment of cancer and autoimmune diseases.
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Affiliation(s)
- Elliot A. Philips
- Departments of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Jia Liu
- Department of Pathology, New York University Grossman School of Medicine, New York, NY 10016, USA
- Laura and Isaac Perlmutter Cancer Center, New York University Langone Health, New York, NY 10016, USA
| | - Audun Kvalvaag
- Kennedy Institute of Rheumatology, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
- Institute for Cancer Research, Oslo University Hospital, Oslo, 0379, Norway
| | - Alexander M. Mørch
- Kennedy Institute of Rheumatology, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
| | - Anna S. Tocheva
- Department of Genetics and Genomic Sciences, Icahn School of Medicine, New York, NY 10029, USA
| | - Charles Ng
- Department of Cell Biology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Hong Liang
- Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Ian M. Ahearn
- Laura and Isaac Perlmutter Cancer Center, New York University Langone Health, New York, NY 10016, USA
| | - Ruimin Pan
- Departments of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Christina C. Luo
- Departments of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Alexander Leithner
- Kennedy Institute of Rheumatology, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
| | - Zhihua Qin
- Laura and Isaac Perlmutter Cancer Center, New York University Langone Health, New York, NY 10016, USA
| | - Yong Zhou
- Integrative Biology and Pharmacology, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Antonio Garcia-España
- Research Unit, Hospital Universitari de Tarragona Joan XXIII, Institut d’Investigació Sanitària Pere Virgili, Universitat Rovira i Virgili, Tarragona, Spain
| | - Adam Mor
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY 10032, USA
| | - Dan R. Littman
- Department of Cell Biology, New York University Grossman School of Medicine, New York, NY 10016, USA
- Howard Hughes Medical Institute, New York, NY 10016, USA
| | - Michael L. Dustin
- Kennedy Institute of Rheumatology, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
| | - Jun Wang
- Department of Pathology, New York University Grossman School of Medicine, New York, NY 10016, USA
- Laura and Isaac Perlmutter Cancer Center, New York University Langone Health, New York, NY 10016, USA
| | - Xiang-Peng Kong
- Departments of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
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3
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Takizawa F, Hashimoto K, Miyazawa R, Ohta Y, Veríssimo A, Flajnik MF, Parra D, Tokunaga K, Suetake H, Sunyer JO, Dijkstra JM. CD4 and LAG-3 from sharks to humans: related molecules with motifs for opposing functions. Front Immunol 2023; 14:1267743. [PMID: 38187381 PMCID: PMC10768021 DOI: 10.3389/fimmu.2023.1267743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 11/27/2023] [Indexed: 01/09/2024] Open
Abstract
CD4 and LAG-3 are related molecules that are receptors for MHC class II molecules. Their major functional differences are situated in their cytoplasmic tails, in which CD4 has an activation motif and LAG-3 an inhibitory motif. Here, we identify shark LAG-3 and show that a previously identified shark CD4-like gene has a genomic location, expression pattern, and motifs similar to CD4 in other vertebrates. In nurse shark (Ginglymostoma cirratum) and cloudy catshark (Scyliorhinus torazame), the highest CD4 expression was consistently found in the thymus whereas such was not the case for LAG-3. Throughout jawed vertebrates, the CD4 cytoplasmic tail possesses a Cx(C/H) motif for binding kinase LCK, and the LAG-3 cytoplasmic tail possesses (F/Y)xxL(D/E) including the previously determined FxxL inhibitory motif resembling an immunoreceptor tyrosine-based inhibition motif (ITIM). On the other hand, the acidic end of the mammalian LAG-3 cytoplasmic tail, which is believed to have an inhibitory function as well, was acquired later in evolution. The present study also identified CD4-1, CD4-2, and LAG-3 in the primitive ray-finned fishes bichirs, sturgeons, and gars, and experimentally determined these sequences for sterlet sturgeon (Acipenser ruthenus). Therefore, with CD4-1 and CD4-2 already known in teleosts (modern ray-finned fish), these two CD4 lineages have now been found within all major clades of ray-finned fish. Although different from each other, the cytoplasmic tails of ray-finned fish CD4-1 and chondrichthyan CD4 not only contain the Cx(C/H) motif but also an additional highly conserved motif which we expect to confer a function. Thus, although restricted to some species and gene copies, in evolution both CD4 and LAG-3 molecules appear to have acquired functional motifs besides their canonical Cx(C/H) and ITIM-like motifs, respectively. The presence of CD4 and LAG-3 molecules with seemingly opposing functions from the level of sharks, the oldest living vertebrates with a human-like adaptive immune system, underlines their importance for the jawed vertebrate immune system. It also emphasizes the general need of the immune system to always find a balance, leading to trade-offs, between activating and inhibiting processes.
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Affiliation(s)
- Fumio Takizawa
- Faculty of Marine Science and Technology, Fukui Prefectural University, Obama, Fukui, Japan
| | - Keiichiro Hashimoto
- Emeritus Professor, Center for Medical Science, Fujita Health University, Toyoake, Aichi, Japan
| | - Ryuichiro Miyazawa
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Yuko Ohta
- Department of Microbiology and Immunology, University of Maryland, Baltimore, MD, United States
| | - Ana Veríssimo
- CIBIO‐InBIO, Research Center in Biodiversity and Genetic Resources, University of Porto, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Vairão, Portugal
| | - Martin F. Flajnik
- Department of Microbiology and Immunology, University of Maryland, Baltimore, MD, United States
| | | | | | - Hiroaki Suetake
- Faculty of Marine Science and Technology, Fukui Prefectural University, Obama, Fukui, Japan
| | - J. Oriol Sunyer
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, United States
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4
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Wang Q, Yang S, Yang K, Li X, Dai Y, Zheng Y, Cao S, Yan Q, Huang X, Wen Y, Zhao Q, Du S, Lang Y, Zhao S, Wu R. CD4 is an important host factor for Japanese encephalitis virus entry and replication in PK-15 cells. Vet Microbiol 2023; 287:109913. [PMID: 38006719 DOI: 10.1016/j.vetmic.2023.109913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 11/07/2023] [Accepted: 11/11/2023] [Indexed: 11/27/2023]
Abstract
Japanese encephalitis virus (JEV) is a flavivirus that is spread through mosquito bites and is the leading cause of viral encephalitis in Asia. JEV can infect a variety of cell types; however, crucial receptor molecules remain unclear. The purpose of this study was to determine whether porcine CD4 protein is a receptor protein that impacts JEV entry into PK15 cells and subsequent viral replication. We confirmed the interaction between the JEV E protein and the CD4 protein through Co-IP, virus binding and internalization, antibody blocking, and overexpression and created a PK-15 cell line with CD4 gene knockdown by CRISPR/Cas9. The results show that CD4 interacts with JEV E and that CD4 knockdown cells altered virus adsorption and internalization, drastically reducing virus attachment. The level of viral transcription in CD4 antibody-blocked cells, vs. control cells, was decreased by 49.1%. Based on these results, we believe that CD4 is a receptor protein for JEVs. Furthermore, most viral receptors appear to be associated with lipid rafts, and colocalization studies demonstrate the presence of CD4 protein on lipid rafts. RT‒qPCR and WB results show that virus replication was suppressed in PK-15-CD4KD cells. The difference in viral titer between KD and WT PK-15 cells peaked at 24 h, and the viral titer in WT PK-15 cells was 5.6 × 106, whereas in PK-15-CD4KD cells, it was only 1.8 × 106, a 64% drop, demonstrating that CD4 deficiency has an effect on the process of viral replication. These findings suggest that JEV enters porcine kidney cells via lipid raft-colocalized CD4, and the proliferation process is positively correlated with CD4.
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Affiliation(s)
- Qi Wang
- Research Center for Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural, Chengdu 611330, China
| | - Shuqing Yang
- Research Center for Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural, Chengdu 611330, China
| | - Ke Yang
- Research Center for Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural, Chengdu 611330, China
| | - Xinran Li
- Research Center for Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural, Chengdu 611330, China
| | - Yu Dai
- Research Center for Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural, Chengdu 611330, China
| | - Yi Zheng
- Research Center for Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural, Chengdu 611330, China
| | - Sanjie Cao
- Research Center for Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural, Chengdu 611330, China
| | - Qigui Yan
- Research Center for Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural, Chengdu 611330, China
| | - Xiaobo Huang
- Research Center for Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural, Chengdu 611330, China
| | - Yiping Wen
- Research Center for Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural, Chengdu 611330, China
| | - Qin Zhao
- Research Center for Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural, Chengdu 611330, China
| | - Senyan Du
- Research Center for Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural, Chengdu 611330, China
| | - Yifei Lang
- Research Center for Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural, Chengdu 611330, China
| | - Shan Zhao
- Research Center for Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural, Chengdu 611330, China
| | - Rui Wu
- Research Center for Swine Diseases, College of Veterinary Medicine, Sichuan Agricultural, Chengdu 611330, China; Sichuan Science-observation Experiment Station of Veterinary Drugs and Veterinary Diagnostic Technology, Ministry of Agriculture, Chengdu 611330, China; National Animal Experiments Teaching Demonstration Center, Sichuan Agricultural University, Chengdu 611330, China.
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5
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Zenere G, Wu C, Midkiff CC, Johnson NM, Grice CP, Wimley WC, Kaur A, Braun SE. Extracellular domain, hinge, and transmembrane determinants affecting surface CD4 expression of a novel anti-HIV chimeric antigen receptor (CAR) construct. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.25.563930. [PMID: 37961145 PMCID: PMC10634810 DOI: 10.1101/2023.10.25.563930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Chimeric antigen receptor (CAR)-T cells have demonstrated clinical potential, but current receptors still need improvements to be successful against chronic HIV infection. In this study, we address some requirements of CAR motifs for strong surface expression of a novel anti-HIV CAR by evaluating important elements in the extracellular, hinge, and transmembrane (TM) domains. When combining a truncated CD4 extracellular domain and CD8α hinge/TM, the novel CAR did not express extracellularly but was detectable intracellularly. By shortening the CD8α hinge, CD4-CAR surface expression was partially recovered and addition of the LYC motif at the end of the CD8α TM fully recovered both intracellular and extracellular CAR expression. Mutation of LYC to TTA or TTC showed severe abrogation of CAR expression by flow cytometry and confocal microscopy. Additionally, we determined that CD4-CAR surface expression could be maximized by the removal of FQKAS motif at the junction of the extracellular domain and the hinge region. CD4-CAR surface expression also resulted in cytotoxic CAR T cell killing of HIV Env+ target cells. In this study, we identified elements that are crucial for optimal CAR surface expression, highlighting the need for structural analysis studies to establish fundamental guidelines of CAR designs.
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Affiliation(s)
- Giorgio Zenere
- Tulane National Primate Research Center, Covington, LA 70433
- BioMedical Sciences Program, Tulane University School of Medicine, New Orleans, LA 70112
| | - Chengxiang Wu
- Tulane National Primate Research Center, Covington, LA 70433
| | | | - Nathan M. Johnson
- Tulane National Primate Research Center, Covington, LA 70433
- BioMedical Sciences Program, Tulane University School of Medicine, New Orleans, LA 70112
| | - Christopher P. Grice
- Tulane National Primate Research Center, Covington, LA 70433
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA 70112
| | - William C. Wimley
- Department of BioChemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA 70112
| | - Amitinder Kaur
- Tulane National Primate Research Center, Covington, LA 70433
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA 70112
| | - Stephen E. Braun
- Tulane National Primate Research Center, Covington, LA 70433
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA 70112
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6
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Three functional mutation sites affect the immune response of pigs through altering the expression pattern and IgV domain of the CD4 protein. BMC Mol Cell Biol 2020; 21:91. [PMID: 33297958 PMCID: PMC7724863 DOI: 10.1186/s12860-020-00333-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 11/24/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The CD4 protein is an important surface marker of T lymphocytes, which can mediate the antigen presentation process by interacting with MHC II and TCR molecules in human and mouse. RESULTS In this study, two haplotypes (A and B) of the CD4 gene were found within Chinese indigenous and Western commercial pig breeds. These two haplotypes were defined by 22 fully linked SNPs in the CDS region of the CD4 gene. The expression level and localization of the CD4 protein were significantly different between haplotypes A and B. Transcriptome analysis revealed that the immune response-related genes and signaling pathways were down-regulated in genotype AA. Finally, three linked functional SNPs were identified, which affected the expression level and membrane localization of the CD4 protein in pigs. These three SNPs led to the replacements of two amino acids in the IgV1 domain of the CD4 protein, and related to the function of the CD4 protein in the immune response. CONCLUSION These three linked SNPs were the key functional mutation sites in the CD4 gene, which played important roles in the immune response, and could be utilized as new molecular markers in breeding for disease resistance in pigs.
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7
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Chatzopoulos K, O'Brien DR, Sotiriou S, Khazaie K, Jen J, Kocher JPA, Markovic SN, Flotte TJ. Aberrant immunohistochemical expression of CD4 as a rare finding in metastatic melanoma. J Cutan Pathol 2020; 47:1223-1226. [PMID: 32594533 DOI: 10.1111/cup.13792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/22/2020] [Accepted: 06/24/2020] [Indexed: 12/15/2022]
Affiliation(s)
- Kyriakos Chatzopoulos
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Daniel R O'Brien
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA
| | - Sotiris Sotiriou
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Jin Jen
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
- Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Jean-Pierre A Kocher
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Thomas J Flotte
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
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8
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Popov EM. Current advances in the X-ray crystallography of proteins. RUSSIAN CHEMICAL REVIEWS 2007. [DOI: 10.1070/rc1995v064n12abeh000194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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9
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Ababou A, Gautel M, Pfuhl M. Dissecting the N-terminal Myosin Binding Site of Human Cardiac Myosin-binding Protein C. J Biol Chem 2007; 282:9204-15. [PMID: 17192269 DOI: 10.1074/jbc.m610899200] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Myosin-binding protein C (MyBP-C) binds to myosin with two binding sites, one close to the N terminus and the other at the C terminus. Here we present the solution structure of one part of the N-terminal binding site, the third immunoglobulin domain of the cardiac isoform of human MyBP-C (cC2) together with a model of its interaction with myosin. Domain cC2 has the beta-sandwich structure expected from a member of the immunoglobulin fold. The C-terminal part of the structure of cC2 is very closely related to telokin, the myosin binding fragment of myosin light chain kinase. Domain cC2 also contains two cysteines on neighboring strands F and G, which would be able to form a disulfide bridge in a similar position as in telokin. Using NMR spectroscopy and isothermal titration calorimetry we demonstrate that cC2 alone binds to a fragment of myosin, S2Delta, with low affinity (kD = 1.1 mM) but exhibits a highly specific binding site. This consists of the C-terminal surface of the C'CFGA' beta-sheet, which includes Glu(301), a residue mutated to Gln in the disease familial hypertrophic cardiomyopathy. The binding site on S2 was identified by a combination of NMR binding experiments of cC2 with S2Delta containing the cardiomyopathy-linked mutation R870H and molecular modeling. This mutation lowers the binding affinity and changes the arrangement of side chains at the interface. Our model of the cC2-S2Delta complex gives a first glimpse of details of the MyBP-C-myosin interaction. Using this model we suggest that most key interactions are between polar amino acids, explaining why the mutations E301Q in cC2 and R870H in S2Delta could be involved in cardiomyopathy. We expect that this model will stimulate future research to further refine the details of this interaction and their importance for cardiomyopathy.
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Affiliation(s)
- Abdessamad Ababou
- Department of Biochemistry, University of Leicester, University Road, Leicester LE1 7RH
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10
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Prabakaran P, Dimitrov AS, Fouts TR, Dimitrov DS. Structure and function of the HIV envelope glycoprotein as entry mediator, vaccine immunogen, and target for inhibitors. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2007; 55:33-97. [PMID: 17586312 PMCID: PMC7111665 DOI: 10.1016/s1054-3589(07)55002-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This chapter discusses the advances of the envelope glycoprotein (Env) structure as related to the interactions of conserved Env structures with receptor molecules and antibodies with implications for the design of vaccine immunogens and inhibitors. The human immunodeficiency virus (HIV) Env binds to cell surface–associated receptor (CD4) and coreceptor (CCR5 or CXCR4) by one of its two non-covalently associated subunits, gp120. The induced conformational changes activate the other subunit (gp41), which causes the fusion of the viral with the plasma cell membranes resulting in the delivery of the viral genome into the cell and the initiation of the infection cycle. As the only HIV protein exposed to the environment, the Env is also a major immunogen to which neutralizing antibodies are directed and a target that is relatively easy to access by inhibitors. A fundamental problem in the development of effective vaccines and inhibitors against HIV is the rapid generation of alterations at high levels of expression during long chronic infection and the resulting significant heterogeneity of the Env. The preservation of the Env function as an entry mediator and limitations on size and expression impose restrictions on its variability and lead to the existence of conserved structures.
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Affiliation(s)
- Ponraj Prabakaran
- Protein Interactions Group, CCRNP, CCR, NCI-Frederick, NIH Frederick, MD 21702, USA
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11
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Murray JL, Hu QX, Navenot JM, Peiper SC. Role of CD4 hinge region in GP120 utilization by immunoglobulin domain 1. Biochem Biophys Res Commun 2002; 292:449-55. [PMID: 11906183 DOI: 10.1006/bbrc.2002.6677] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Immunoglobulin-like domain 1 of CD4 (D1-CD4) promotes HIV infection by binding the envelope glycoprotein (ENV) and exposing its coreceptor-binding site. To study CD4-ENV-coreceptor interactions, we characterized hybrid receptors having domains 1 and 2 of CD4 (D1D2-CD4) joined to the N-terminus of chemokine receptors CCR5, CXCR4, CXCR2, and DARC. Hybrid receptors showed conserved ENV-coreceptor specificity in cell-cell fusion assays. Although D1D2-CD4-CCR5 was sufficient to permit ENV-mediated fusion, D1-CD4-CCR5 and human D1/mouse D2-CD4-CCR5 lacked CD4 function and binding to a neutralizing antibody mapped to D1-CD4. Chimeric D1D2-CD4 joined to CCR5 revealed that the C-terminal 20 residues of human D2-CD4 are required for efficient ENV-mediated fusion. Mutagenesis of hybrid receptors showed the importance of residues forming D1-D2 CD4 interdomain contacts and hinge region proximal residues. Mutagenesis of WT human CD4 confirmed that residues forming D1-D2 interdomain contacts and hinge-region proximal residues contribute positively to CD4 activity in the full-length receptor.
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Affiliation(s)
- James L Murray
- Henry Vogt Cancer Research Center, University of Louisville, Louisville, Kentucky 40202, USA
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12
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Xiong Y, Kern P, Chang H, Reinherz E. T Cell Receptor Binding to a pMHCII Ligand Is Kinetically Distinct from and Independent of CD4. J Biol Chem 2001; 276:5659-67. [PMID: 11106664 DOI: 10.1074/jbc.m009580200] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Immune recognition of pMHCII ligands by a helper T lymphocyte involves its antigen-specific T cell receptor (TCR) and CD4 coreceptor. We have characterized the binding of both molecules to the same pMHCII. The D10 alphabeta TCR heterodimer binds to conalbumin/I-A(k) with virtually identical kinetics and affinity as the single chain ValphaVbeta domain module (scD10) (Kd = 6-8 microm). The CD4 ectodomain does not alter either interaction. Moreover, CD4 alone demonstrates weak pMHCII binding (Kd = 200 microm), with no discernable affinity for the alphabeta TCR heterodimer. Hence, rather than providing a major contribution to binding energy, the critical role for the coreceptor in antigen-specific activation likely results from transient inducible recruitment of the CD4 cytoplasmic tail-associated lck tyrosine kinase to the pMHCII-ligated TCR complex.
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MESH Headings
- Antigen Presentation
- CD4 Antigens/genetics
- CD4 Antigens/metabolism
- Genes, MHC Class II
- Histocompatibility Antigens Class II
- Humans
- Kinetics
- Ligands
- Lymphocyte Activation
- Models, Immunological
- Peptide Fragments/genetics
- Peptide Fragments/metabolism
- Peptides/metabolism
- Protein Binding
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/metabolism
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/metabolism
- Recombinant Fusion Proteins/immunology
- Recombinant Fusion Proteins/metabolism
- Signal Transduction
- T-Lymphocytes, Helper-Inducer/immunology
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Affiliation(s)
- Y Xiong
- Laboratory of Immunobiology, Dana-Farber Cancer Institute and Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115, USA
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13
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Barnes LM, Bentley CM, Dickson AJ. Advances in animal cell recombinant protein production: GS-NS0 expression system. Cytotechnology 2000; 32:109-23. [PMID: 19002973 PMCID: PMC3449689 DOI: 10.1023/a:1008170710003] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The production of recombinant proteins using mammalian cell expression systems is of growing importance within biotechnology, largely due to the ability of specific mammalian cells to carry out post-translational modifications of the correct fidelity. The Glutamine Synthetase-NS0 system is now one such industrially important expression system.Glutamine synthetase catalyses the formation ofglutamine from glutamate and ammonia. NS0 cellscontain extremely low levels of endogenous glutaminesynthetase activity, therefore exogenous glutaminesynthetase can be used efficiently as a selectablemarker to identify successful transfectants in theabsence of glutamine in the media. In addition, theinclusion of methionine sulphoximine, an inhibitor ofglutamine synthetase activity, enables furtherselection of those clones producing relatively highlevels of transfected glutamine synthetase and henceany heterologous gene which is coupled to it. Theglutamine synthetase system technology has been usedfor research and development purposes during thisdecade and its importance is clearly demonstrated nowthat two therapeutic products produced using thissystem have reached the market place.
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Affiliation(s)
- L M Barnes
- 2.205 School of Biological Sciences, University of Manchester, Stopford Building, Oxford Road, Manchester, M13 9PT (Author for correspondence)
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14
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Koskinen R, Lamminmäki U, Tregaskes CA, Salomonsen J, Young JR, Vainio O. Cloning and Modeling of the First Nonmammalian CD4. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.7.4115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
We have cloned and sequenced the first nonmammalian CD4 cDNA from the chicken using the COS cell expression method. Chicken CD4 contains four extracellular Ig domains that, in analogy to mammalian CD4, are in the order V, C2, V, and C2. The molecule is 24% identical with both human and mouse sequences. The extracellular domains were modeled using human and rat CD4 crystal structures as templates. In the first domain there are two extra Cys residues that are at suitable distance to form an intra-β-sheet disulfide bridge in addition to the canonical one in the V domain. The region responsible for the interaction with MHC class II is relatively nonconserved in chicken. However, there are positively charged amino acids in the C″ region of the N-terminal domain that may mediate the association to the negatively charged residues of the MHC class II β-chain. Molecular modeling also implies that the membrane-proximal domain mediates dimerization of chicken CD4 in a similar way as it does for human CD4. Furthermore, the cytoplasmic tail is highly conserved, containing the protein tyrosine kinase p56lck recognition site that is preceded by an adjacent di-leucine motif for the internalization of the molecule. Interestingly, there are no Ser residues in the cytoplasmic part, which may explain the slow down-regulation of chicken CD4 after phorbol ester stimulation.
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Affiliation(s)
- Riitta Koskinen
- †Medical Microbiology and
- *Turku Immunology Center and Departments of
| | - Urpo Lamminmäki
- ‡Biotechnology, Turku University, Turku, Finland
- *Turku Immunology Center and Departments of
| | - Clive A. Tregaskes
- §Institute for Animal Health, Compton, United Kingdom; and
- *Turku Immunology Center and Departments of
| | - Jan Salomonsen
- ¶Department of Virology and Immunology, Royal Veterinary and Agricultural University, Frederiksberg, Denmark
- *Turku Immunology Center and Departments of
| | - John R. Young
- §Institute for Animal Health, Compton, United Kingdom; and
- *Turku Immunology Center and Departments of
| | - Olli Vainio
- †Medical Microbiology and
- *Turku Immunology Center and Departments of
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15
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Zelus BD, Wessner DR, Williams RK, Pensiero MN, Phibbs FT, deSouza M, Dveksler GS, Holmes KV. Purified, soluble recombinant mouse hepatitis virus receptor, Bgp1(b), and Bgp2 murine coronavirus receptors differ in mouse hepatitis virus binding and neutralizing activities. J Virol 1998; 72:7237-44. [PMID: 9696818 PMCID: PMC109946 DOI: 10.1128/jvi.72.9.7237-7244.1998] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/1998] [Accepted: 05/28/1998] [Indexed: 11/20/2022] Open
Abstract
Mouse hepatitis virus receptor (MHVR) is a murine biliary glycoprotein (Bgp1(a)). Purified, soluble MHVR expressed from a recombinant vaccinia virus neutralized the infectivity of the A59 strain of mouse hepatitis virus (MHV-A59) in a concentration-dependent manner. Several anchored murine Bgps in addition to MHVR can also function as MHV-A59 receptors when expressed at high levels in nonmurine cells. To investigate the interactions of these alternative MHVR glycoproteins with MHV, we expressed and purified to apparent homogeneity the extracellular domains of several murine Bgps as soluble, six-histidine-tagged glycoproteins, using a baculovirus expression system. These include MHVR isoforms containing four or two extracellular domains and the corresponding Bgp1(b) glycoproteins from MHV-resistant SJL/J mice, as well as Bgp2 and truncation mutants of MHVR and Bgp1(b) comprised of the first two immunoglobulin-like domains. The soluble four-domain MHVR glycoprotein (sMHVR[1-4]) had fourfold more MHV-A59 neutralizing activity than the corresponding soluble Bgp1(b) (sBgp1(b)) glycoprotein and at least 1,000-fold more neutralizing activity than sBgp2. Although virus binds to the N-terminal domain (domain 1), soluble truncation mutants of MHVR and Bgp1(b) containing only domains 1 and 2 bound virus poorly and had 10- and 300-fold less MHV-A59 neutralizing activity than the corresponding four-domain glycoproteins. In contrast, the soluble MHVR glycoprotein containing domains 1 and 4 (sMHVR[1,4]) had as much neutralizing activity as the four-domain glycoprotein, sMHVR[1-4]. Thus, the virus neutralizing activity of MHVR domain 1 appears to be enhanced by domain 4. The sBgp1(b)[1-4] glycoprotein had 500-fold less neutralizing activity for MHV-JHM than for MHV-A59. Thus, MHV strains with differences in S-glycoprotein sequence, tissue tropism, and virulence can differ in the ability to utilize the various murine Bgps as receptors.
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Affiliation(s)
- B D Zelus
- Department of Microbiology, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA
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16
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Fang DC, Fabian P, Szekely Z, Fu XY, Tang TH, Csizmadia IG. Structure and stability of ammonium-sulfate and guanidium-sulfate complex. ACTA ACUST UNITED AC 1998. [DOI: 10.1016/s0166-1280(98)90233-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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17
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Moir S, Perreault J, Poulin L. Postbinding events mediated by human immunodeficiency virus type 1 are sensitive to modifications in the D4-transmembrane linker region of CD4. J Virol 1996; 70:8019-28. [PMID: 8892926 PMCID: PMC190875 DOI: 10.1128/jvi.70.11.8019-8028.1996] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Evidence from both structural and functional studies of the CD4 molecule suggests that several domains, including the transmembrane (TM) domain and the adjoining extracellular region (D4-TM linker), contribute to the post-gp12O-binding events leading to human immunodeficiency virus-mediated membrane fusion. To investigate such a role in syncytium formation and cell-free infectivity, we generated several deletion and substitution mutations in the TM and D4-TM linker regions of the CD4 molecule. We found that while the TM domain of CD4 was dispensable for cell-cell and virus-cell interactions, modifications in the D4-TM linker led to perturbations in both processes. Deletion of the five amino acid residues linking D4 to the TM domain resulted in a delayed and reduced capacity to form syncytia, whereas replacement of the residues with the heterologous sequence from the CD8 molecule restored the kinetic profile to wild-type CD4 levels. On the other hand, both mutants of the CD4 D4-TM linker demonstrated delayed cell-free human immunodeficiency virus type 1 infectivity profiles. The defective fusion capacity may be linked to structural perturbations identified with anti-CD4 monoclonal antibodies in the D1-D2 interface and D3 domain of the deletion mutant yet absent in D1 and D4. While all cells were found to bind comparable levels of gp120, both D4-TM linker mutants appeared to induce a decrease in the V3 loop exposure of bound gp120. This underexposure may explain the delays in cell-free infectivities observed for both of these mutants. Together, these findings confirm a role for regions of the CD4 molecule located outside D1 in post-gp120-binding events and suggest that the D4-TM interface contributes to the conformational changes that direct the fusion process.
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Affiliation(s)
- S Moir
- Centre de Recherche en Infectiologie du Centre Hospitalier Universitaire de Québec, Canada
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18
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Székely Z, Kónya Z, Becskei A, Goldring WP, Perczel A, Penke B, Molnár J, Michejda CF, Aszalós A, Csizmadia IG. Suggested binding mechanism of the HIV-gp120 to its CD4 receptor. ACTA ACUST UNITED AC 1996. [DOI: 10.1016/s0166-1280(96)04501-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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19
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Affiliation(s)
- R L Brady
- Department of Biochemistry, University of Bristol, University Walk, UK
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20
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Tropak MB, Jansz GF, Abramow-Newerly W, Roder JC. Conservation of functionally important epitopes on myelin associated glycoprotein (MAG). Comp Biochem Physiol B Biochem Mol Biol 1995; 112:345-54. [PMID: 7584863 DOI: 10.1016/0305-0491(95)00087-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Phylogenetic conservation of protein domains often points to functionally important regions. As a step toward mapping these sites on myelin associated glycoprotein (MAG) we have determined the species distribution of epitopes recognized by a panel of anti-MAG antibodies (Ab). Monoclonal antibodies (mAb) B11F7, GenS3 and 28 recognized MAG only in mammalian species. However, the mAb 513 which inhibits MAG binding recognized a conformational epitope in a wider distribution of species including, human (Homo sapiens), bovine (Bos taurus), rat (Rattus norvegicus), chicken (Gallus gallus), quail (Coturnix coturnix japonica), lizard (Iguana iguana), snake (Thamnophis sirtalis), frog (Xenopus laevis) and turtle (all tetrapods) but not in goldfish (Crassius aurata) (a teleost). However, only MAG from mammals was shown to bind rat dorsal ganglion neurons (DRGs) suggesting that structures additional to those recognized by mAb 513 must be involved in function. Antibody 28, on the other hand, recognized only MAG species which bound to neurons, suggesting that this epitope, in comparison with mAb 513, more closely represented the functionally important region of MAG. Observed species differences in glycosylation of MAG may be functionally significant. A newly developed polyclonal Ab against MAG recognized the protein in tetrapods and teleosts, but not chondricthyes. The results show that MAG is present in a wide spectrum of species.
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Affiliation(s)
- M B Tropak
- Samuel Lunenfeld Research Institute, Mt. Sinai Hospital, Toronto, Ontario, Canada
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21
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Székely, Z. A new approach for an HIV docking-inhibitor drug designed on the basis of the dual recognition/binding hypothesis between the CD4 receptor and the envelope glycoprotein of the HIV. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/0166-1280(95)04238-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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22
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Abstract
Several new structural motifs found in cell surface adhesion receptors have been described in the past few years. Also, several two-domain structures of extracellular portions of cell surface proteins have been reported. Structural models for complexes between receptors and counter-receptors have been proposed. The first reports on carbohydrate conformation in intact glycoprotein domains have recently appeared. These new data are presented within a more general review of the field of cell adhesion receptors.
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Affiliation(s)
- G Wagner
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115
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