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Tam EH, Peng Y, Cheah MXY, Yan C, Xiao T. Neutralizing antibodies to block viral entry and for identification of entry inhibitors. Antiviral Res 2024; 224:105834. [PMID: 38369246 DOI: 10.1016/j.antiviral.2024.105834] [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: 10/31/2023] [Revised: 02/01/2024] [Accepted: 02/07/2024] [Indexed: 02/20/2024]
Abstract
Neutralizing antibodies (NAbs) are naturally produced by our immune system to combat viral infections. Clinically, neutralizing antibodies with potent efficacy and high specificity have been extensively used to prevent and treat a wide variety of viral infections, including Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), Human Immunodeficiency Virus (HIV), Dengue Virus (DENV) and Hepatitis B Virus (HBV). An overwhelmingly large subset of clinically effective NAbs operates by targeting viral envelope proteins to inhibit viral entry into the host cell. Binding of viral envelope protein to the host receptor is a critical rate limiting step triggering a cascade of downstream events, including endocytosis, membrane fusion and pore formation to allow viral entry. In recent years, improved structural knowledge on these processes have allowed researchers to also leverage NAbs as an indispensable tool in guiding discovery of novel antiviral entry inhibitors, providing drug candidates with high efficacy and pan-genus specificity. This review will summarize the latest progresses on the applications of NAbs as effective entry inhibitors and as important tools to develop antiviral therapeutics by high-throughput drug screenings, rational design of peptidic entry inhibitor mimicking NAbs and in silico computational modeling approaches.
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Affiliation(s)
- Ee Hong Tam
- School of Biological Sciences, Nanyang Technological University 637551, Singapore; Institute of Structural Biology, Nanyang Technological University 636921, Singapore
| | - Yu Peng
- School of Biological Sciences, Nanyang Technological University 637551, Singapore; Institute of Structural Biology, Nanyang Technological University 636921, Singapore
| | - Megan Xin Yan Cheah
- Institute of Molecular and Cell Biology, A*STAR (Agency of Science, Technology and Research) 138673, Singapore
| | - Chuan Yan
- Institute of Molecular and Cell Biology, A*STAR (Agency of Science, Technology and Research) 138673, Singapore
| | - Tianshu Xiao
- School of Biological Sciences, Nanyang Technological University 637551, Singapore; Institute of Structural Biology, Nanyang Technological University 636921, Singapore.
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Gadhe CG, Kothandan G, Cho SJ. Characterization of Binding Mode of the Heterobiaryl gp120 Inhibitor in HIV-1 Entry: A Molecular Docking and Dynamics Simulation Study. B KOREAN CHEM SOC 2013. [DOI: 10.5012/bkcs.2013.34.8.2466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Straightforward selection of broadly neutralizing single-domain antibodies targeting the conserved CD4 and coreceptor binding sites of HIV-1 gp120. J Virol 2012; 87:1137-49. [PMID: 23152508 DOI: 10.1128/jvi.00461-12] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Few broadly neutralizing antibodies targeting determinants of the HIV-1 surface envelope glycoprotein (gp120) involved in sequential binding to host CD4 and chemokine receptors have been characterized. While these epitopes show low diversity among various isolates, HIV-1 employs many strategies to evade humoral immune response toward these sensitive sites, including a carbohydrate shield, low accessibility to these buried cavities, and conformational masking. Using trimeric gp140, free or bound to a CD4 mimic, as immunogens in llamas, we selected a panel of broadly neutralizing single-domain antibodies (sdAbs) that bind to either the CD4 or the coreceptor binding site (CD4BS and CoRBS, respectively). When analyzed as monomers or as homo- or heteromultimers, the best sdAb candidates could not only neutralize viruses carrying subtype B envelopes, corresponding to the Env molecule used for immunization and selection, but were also efficient in neutralizing a broad panel of envelopes from subtypes A, C, G, CRF01_AE, and CRF02_AG, including tier 3 viruses. Interestingly, sdAb multimers exhibited a broader neutralizing activity spectrum than the parental sdAb monomers. The extreme stability and high recombinant production yield combined with their broad neutralization capacity make these sdAbs new potential microbicide candidates for HIV-1 transmission prevention.
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Heidebrecht T, Fish A, von Castelmur E, Johnson KA, Zaccai G, Borst P, Perrakis A. Binding of the J-binding protein to DNA containing glucosylated hmU (base J) or 5-hmC: evidence for a rapid conformational change upon DNA binding. J Am Chem Soc 2012; 134:13357-65. [PMID: 22775585 DOI: 10.1021/ja303423t] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Base J (β-D-glucosyl-hydroxymethyluracil) was discovered in the nuclear DNA of some pathogenic protozoa, such as trypanosomes and Leishmania, where it replaces a fraction of base T. We have found a J-Binding Protein 1 (JBP1) in these organisms, which contains a unique J-DNA binding domain (DB-JBP1) and a thymidine hydroxylase domain involved in the first step of J biosynthesis. This hydroxylase is related to the mammalian TET enzymes that hydroxylate 5-methylcytosine in DNA. We have now studied the binding of JBP1 and DB-JBP1 to oligonucleotides containing J or glucosylated 5-hydroxymethylcytosine (glu-5-hmC) using an equilibrium fluorescence polarization assay. We find that JBP1 binds glu-5-hmC-DNA with an affinity about 40-fold lower than J-DNA (~400 nM), which is still 200 times higher than the JBP1 affinity for T-DNA. The discrimination between glu-5-hmC-DNA and T-DNA by DB-JBP1 is about 2-fold less, but enough for DB-JBP1 to be useful as a tool to isolate 5-hmC-DNA. Pre-steady state kinetic data obtained in a stopped-flow device show that the initial binding of JBP1 to glucosylated DNA is very fast with a second order rate constant of 70 μM(-1) s(-1) and that JBP1 binds to J-DNA or glu-5-hmC-DNA in a two-step reaction, in contrast to DB-JBP1, which binds in a one-step reaction. As the second (slower) step in binding is concentration independent, we infer that JBP1 undergoes a conformational change upon binding to DNA. Global analysis of pre-steady state and equilibrium binding data supports such a two-step mechanism and allowed us to determine the kinetic parameters that describe it. This notion of a conformational change is supported by small-angle neutron scattering experiments, which show that the shape of JBP1 is more elongated in complex with DNA. The conformational change upon DNA binding may allow the hydroxylase domain of JBP1 to make contact with the DNA and hydroxylate T's in spatial proximity, resulting in regional introduction of base J into the DNA.
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Affiliation(s)
- Tatjana Heidebrecht
- Division of Biochemistry, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
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Grupping K, Selhorst P, Michiels J, Vereecken K, Heyndrickx L, Kessler P, Vanham G, Martin L, Ariën KK. MiniCD4 protein resistance mutations affect binding to the HIV-1 gp120 CD4 binding site and decrease entry efficiency. Retrovirology 2012; 9:36. [PMID: 22551420 PMCID: PMC3408336 DOI: 10.1186/1742-4690-9-36] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Accepted: 05/02/2012] [Indexed: 11/10/2022] Open
Abstract
Background Binding of the viral envelope protein (Env), and particularly of its gp120 subunit, to the cellular CD4 receptor is the first essential step of the HIV-1 entry process. The CD4 binding site (CD4bs) of gp120, and especially a recessed cavity occupied by the CD4 Phe43 residue, are known to be highly conserved among the different circulating subtypes and therefore constitute particularly interesting targets for vaccine and drug design. The miniCD4 proteins are a promising class of CD4bs inhibitors. Studying virus evolution under pressure of CD4bs inhibitors could provide insight on the gp120-CD4 interaction and viral entry. Results The present study reports on the resistance induction of two subtype B HIV-1 against the most active miniCD4, M48U1, and its ancestor, M48, and how these mutated positions affect CD4bs recognition, entry efficiency, and sensitivity to other CD4bs inhibitors. Resistance against M48U1 was always associated with S375R/N substitution in both BaL and SF162; M48 resistance was associated with D474N substitution in SF162 and with H105Y substitution in BaL. In addition, some other mutations at position V255 and G471 were of importance for SF162 resistant viruses. Except for 474, all of these mutated positions are conserved, and introducing them into an SF162 Env expressing infectious molecular clone (pBRNL4.3 SF162) resulted in decreased entry efficiency. Furthermore, resistant mutants showed at least some cross-resistance towards other CD4bs inhibitors, the V3 monoclonal antibody 447-52D and some even against the monoclonal antibody 17b, of which the epitope overlaps the co-receptor binding site. Conclusions The mutations H105Y, V255M, S375R/N, G471R/E, and D474N are found to be involved in resistance towards M48 and M48U1. All mutated positions are part of, or in close proximity to, the CD4bs; most are highly conserved, and all have an impact on the entry efficiency, suggesting their importance for optimal virus infectivity.
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Affiliation(s)
- Katrijn Grupping
- Virology Unit, Department of Biomedical Sciences, Institute of Tropical Medicine of Antwerp, Antwerp, Belgium
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Gadhe CG, Kothandan G, Madhavan T, Cho SJ. Molecular modeling study of HIV-1 gp120 attachment inhibitors. Med Chem Res 2011. [DOI: 10.1007/s00044-011-9711-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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A tyrosine-sulfated CCR5-mimetic peptide promotes conformational transitions in the HIV-1 envelope glycoprotein. J Virol 2011; 85:7563-71. [PMID: 21613393 DOI: 10.1128/jvi.00630-11] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The HIV-1 envelope glycoprotein is a trimeric complex of heterodimers composed of a surface glycoprotein, gp120, and a transmembrane component, gp41. The association of this complex with CD4 stabilizes the coreceptor-binding site of gp120 and promotes the exposure of the gp41 helical region 1 (HR1). Here, we show that a 15-amino-acid peptide mimetic of the HIV-1 coreceptor CCR5 fused to a dimeric antibody Fc domain (CCR5mim-Ig) bound two gp120 molecules per envelope glycoprotein complex and by itself promoted HR1 exposure. CCR5mim-Ig also stabilized the association of a CD4-mimetic peptide with the envelope glycoprotein. A fusion of the CD4- and CCR5-mimetic peptides, DM1, bound gp120 and neutralized R5, R5X4, and X4 HIV-1 isolates comparably to CD4, and they did so markedly more efficiently than either peptide alone. Our data indicate that the potency of DM1-Ig derives from its avidity for the HIV-1 envelope glycoprotein trimer and from the bidirectional induction of its receptor-mimetic components. DM1 has significant advantages over other inhibitors that target both coreceptor and CD4-binding sites, and it may serve as a lead for a new class of HIV-1 inhibitor peptides.
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Martin G, Burke B, Thaï R, Dey AK, Combes O, Ramos OHP, Heyd B, Geonnotti AR, Montefiori DC, Kan E, Lian Y, Sun Y, Abache T, Ulmer JB, Madaoui H, Guérois R, Barnett SW, Srivastava IK, Kessler P, Martin L. Stabilization of HIV-1 envelope in the CD4-bound conformation through specific cross-linking of a CD4 mimetic. J Biol Chem 2011; 286:21706-16. [PMID: 21487012 DOI: 10.1074/jbc.m111.232272] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
CD4 binding on gp120 leads to the exposure of highly conserved regions recognized by the HIV co-receptor CCR5 and by CD4-induced (CD4i) antibodies. A covalent gp120-CD4 complex was shown to elicit CD4i antibody responses in monkeys, which was correlated with control of the HIV virus infection (DeVico, A., Fouts, T., Lewis, G. K., Gallo, R. C., Godfrey, K., Charurat, M., Harris, I., Galmin, L., and Pal, R. (2007) Proc. Natl. Acad. Sci. U.S.A. 104, 17477-17482). Because the inclusion of CD4 in a vaccine formulation should be avoided, due to potential autoimmune reactions, we engineered small sized CD4 mimetics (miniCD4s) that are poorly immunogenic and do not induce anti-CD4 antibodies. We made covalent complexes between such an engineered miniCD4 and gp120 or gp140, through a site-directed coupling reaction. These complexes were recognized by CD4i antibodies as well as by the HIV co-receptor CCR5. In addition, they elicit CD4i antibody responses in rabbits and therefore represent potential vaccine candidates that mimic an important HIV fusion intermediate, without autoimmune hazard.
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Affiliation(s)
- Grégoire Martin
- Commissariat à l'Energie Atomique, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, Gif-sur-Yvette F-91191, France
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Lebbink JHG, Fish A, Reumer A, Natrajan G, Winterwerp HHK, Sixma TK. Magnesium coordination controls the molecular switch function of DNA mismatch repair protein MutS. J Biol Chem 2010; 285:13131-41. [PMID: 20167596 PMCID: PMC2857095 DOI: 10.1074/jbc.m109.066001] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The DNA mismatch repair protein MutS acts as a molecular switch. It toggles between ADP and ATP states and is regulated by mismatched DNA. This is analogous to G-protein switches and the regulation of their “on” and “off” states by guanine exchange factors. Although GDP release in monomeric GTPases is accelerated by guanine exchange factor-induced removal of magnesium from the catalytic site, we found that release of ADP from MutS is not influenced by the metal ion in this manner. Rather, ADP release is induced by the binding of mismatched DNA at the opposite end of the protein, a long-range allosteric response resembling the mechanism of activation of heterotrimeric GTPases. Magnesium influences switching in MutS by inducing faster and tighter ATP binding, allowing rapid downstream responses. MutS mutants with decreased affinity for the metal ion are impaired in fast switching and in vivo mismatch repair. Thus, the G-proteins and MutS conceptually employ the same efficient use of the high energy cofactor: slow hydrolysis in the absence of a signal and fast conversion to the active state when required.
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Affiliation(s)
- Joyce H G Lebbink
- Division of Biochemistry and Center for Biomedical Genetics, Netherlands Cancer Institute, 1066 CX Amsterdam, The Netherlands.
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Reed D, Shen Y, Shelat AA, Arnold LA, Ferreira AM, Zhu F, Mills N, Smithson DC, Regni CA, Bashford D, Cicero SA, Schulman BA, Jochemsen AG, Guy RK, Dyer MA. Identification and characterization of the first small molecule inhibitor of MDMX. J Biol Chem 2010; 285:10786-96. [PMID: 20080970 DOI: 10.1074/jbc.m109.056747] [Citation(s) in RCA: 157] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The p53 pathway is disrupted in virtually every human tumor. In approximately 50% of human cancers, the p53 gene is mutated, and in the remaining cancers, the pathway is dysregulated by genetic lesions in other genes that modulate the p53 pathway. One common mechanism for inactivation of the p53 pathway in tumors that express wild-type p53 is increased expression of MDM2 or MDMX. MDM2 and MDMX bind p53 and inhibit its function by distinct nonredundant mechanisms. Small molecule inhibitors and small peptides have been developed that bind MDM2 in the p53-binding pocket and displace the p53 protein, leading to p53-mediated cell cycle exit and apoptosis. To date, peptide inhibitors of MDMX have been developed, but no small molecule inhibitors have been reported. We have developed biochemical and cell-based assays for high throughput screening of chemical libraries to identify MDMX inhibitors and identified the first MDMX inhibitor SJ-172550. This compound binds reversibly to MDMX and effectively kills retinoblastoma cells in which the expression of MDMX is amplified. The effect of SJ-172550 is additive when combined with an MDM2 inhibitor. Results from a series of biochemical and structural modeling studies suggest that SJ-172550 binds the p53-binding pocket of MDMX, thereby displacing p53. This lead compound is a useful chemical scaffold for further optimization of MDMX inhibitors that may eventually be used to treat pediatric cancers and various adult tumors that overexpress MDMX or have similar genetic lesions. When combined with selective MDM2 inhibitors, SJ-172550 may also be useful for treating tumors that express wild-type p53.
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Affiliation(s)
- Damon Reed
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
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Teixeira C, Serradji N, Maurel F, Barbault F. Docking and 3D-QSAR studies of BMS-806 analogs as HIV-1 gp120 entry inhibitors. Eur J Med Chem 2009; 44:3524-32. [DOI: 10.1016/j.ejmech.2009.03.028] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Revised: 01/27/2009] [Accepted: 03/19/2009] [Indexed: 10/21/2022]
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Abstract
We report the development of a system combining the capabilities of fluorescence imaging spectroscopy (x, lambda, I), fluorescence lifetime (tau) and static and dynamic fluorescence anisotropy (r), enabling the wide-field measurement of the spectroscopic parameters of fluorophores: (x, lambda, I, tau, r). The system employs a frequency domain data collection strategy with a modulated light emitting diode as the light source. A polarization rotator placed in the excitation path after a polarizer allows alternating parallel and perpendicular images to be collected without moving parts. A second polarizer on the emission side serves as the analyzer, leading to estimations of the wavelength-dependent dynamic anisotropies. The spectrograph has a nominal range of 365-920 nm; however, the light-emitting diodes and filter sets used in this study restricted the usable range from about 510 to 700 nm. The system was tested on rhodamine 6G (R6G) solutions containing 0, 15, 37, 45, 59, 74 and 91 glycerol. These experiments gave rotational diffusion results comparing favourably with literature values while also demonstrating a trend towards shorter measured lifetimes at high refractive index. The ability of the system to resolve mixtures was tested on mixtures of anti-human IgG-FITC (gamma-chain-specific) and R6G. These fluorophores have similar lifetimes but could be separated using anisotropy parameters. The imaging capabilities of the system were tested on mixtures of fluorescent beads with glycerol solutions of R6G.
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Affiliation(s)
- Y Zhou
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham, United Kingdom
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Schoof S, Baumann S, Ellinger B, Arndt HD. A fluorescent probe for the 70 S-ribosomal GTPase-associated center. Chembiochem 2009; 10:242-5. [PMID: 19072817 DOI: 10.1002/cbic.200800642] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Sebastian Schoof
- Technische Universität Dortmund, Fakultät Chemie, Otto-Hahn-Str. 6, 44221 Dortmund, Germany
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Stricher F, Huang CC, Descours A, Duquesnoy S, Combes O, Decker JM, Kwon YD, Lusso P, Shaw GM, Vita C, Kwong PD, Martin L. Combinatorial optimization of a CD4-mimetic miniprotein and cocrystal structures with HIV-1 gp120 envelope glycoprotein. J Mol Biol 2008; 382:510-24. [PMID: 18619974 PMCID: PMC2625307 DOI: 10.1016/j.jmb.2008.06.069] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2008] [Revised: 06/19/2008] [Accepted: 06/23/2008] [Indexed: 01/07/2023]
Abstract
Miniproteins provide a bridge between proteins and small molecules. Here we adapt methods from combinatorial chemistry to optimize CD4M33, a synthetic miniprotein into which we had previously transplanted the HIV-1 gp120 binding surface of the CD4 receptor. Iterative deconvolution of generated libraries produced CD4M47, a derivative of CD4M33 that had been optimized at four positions. Surface plasmon resonance demonstrated fourfold to sixfold improvement in CD4M47 affinity for gp120 to a level about threefold tighter than that of CD4 itself. Assessment of the neutralization properties of CD4M47 against a diverse range of isolates spanning from HIV-1 to SIVcpz showed that CD4M47 retained the extraordinary breadth of the parent CD4M33, but yielded only limited improvements in neutralization potencies. Crystal structures of CD4M47 and a phenylalanine variant ([Phe23]M47) were determined at resolutions of 2.4 and 2.6 A, in ternary complexes with HIV-1 gp120 and the 17b antibody. Analysis of these structures revealed a correlation between mimetic affinity for gp120 and overall mimetic-gp120 interactive surface. A correlation was also observed between CD4- and mimetic-induced gp120 structural similarity and CD4- and mimetic-induced gp120 affinity for the CCR5 coreceptor. Despite mimetic substitutions, including a glycine-to-(d)-proline change, the gp120 conformation induced by CD4M47 was as close or closer to the conformation induced by CD4 as the one induced by the parent CD4M33. Our results demonstrate the ability of combinatorial chemistry to optimize a disulfide-containing miniprotein, and of structural biology to decipher the resultant interplay between binding affinity, neutralization breadth, molecular mimicry, and induced affinity for CCR5.
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Affiliation(s)
| | - Chih-chin Huang
- Vaccine Research Center, NIAID, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Anne Descours
- CEA, iBiTecS, SIMOPRO, Gif-sur-Yvette, F-91191, France
| | | | | | - Julie M. Decker
- Howard Hughes Medical Institute, Department of Medicine, Department of Microbiology, University of Alabama at Birmingham, Alabama 35294, United States
| | - Young Do Kwon
- Vaccine Research Center, NIAID, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Paolo Lusso
- Unit of Human Virology, San Raffaele Scientific Institute, 20132 Milan, Italy
| | - George M. Shaw
- Howard Hughes Medical Institute, Department of Medicine, Department of Microbiology, University of Alabama at Birmingham, Alabama 35294, United States
| | - Claudio Vita
- CEA, iBiTecS, SIMOPRO, Gif-sur-Yvette, F-91191, France, Deceased
| | - Peter D. Kwong
- Vaccine Research Center, NIAID, National Institutes of Health, Bethesda, Maryland 20892, United States, to whom correspondence should be addressed: PDK: Tel: (+1)-301-594-8685; Fax: (+1)-301-480-2658; e-mail: , LM: Tel: (+33)-169087133; Fax: (+33)-169089071; e-mail:
| | - Loïc Martin
- CEA, iBiTecS, SIMOPRO, Gif-sur-Yvette, F-91191, France, to whom correspondence should be addressed: PDK: Tel: (+1)-301-594-8685; Fax: (+1)-301-480-2658; e-mail: , LM: Tel: (+33)-169087133; Fax: (+33)-169089071; e-mail:
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Martin G, Sun Y, Heyd B, Combes O, Ulmer JB, Descours A, Barnett SW, Srivastava IK, Martin L. A simple one-step method for the preparation of HIV-1 envelope glycoprotein immunogens based on a CD4 mimic peptide. Virology 2008; 381:241-50. [PMID: 18835005 DOI: 10.1016/j.virol.2008.08.039] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 07/23/2008] [Accepted: 08/23/2008] [Indexed: 11/26/2022]
Abstract
To counteract the problems associated with the purification of HIV envelope, we developed a new purification method exploiting the high affinity of a peptide mimicking CD4 towards the viral glycoprotein. This miniCD4 was used as a ligand in affinity chromatography and allowed the separation in one step of HIV envelope monomer from cell supernatant and the capture of pre-purified trimer. This simple and robust method of purification yielded to active and intact HIV envelopes as proved by the binding of CCR5 HIV co-receptor, CD4 and a panel of well-characterized monoclonal antibodies. The immunogenicity of miniCD4-purified HIV envelope was further assessed in rats. The analysis of the humoral response indicated that elicited antibodies were able to recognize a broad range of HIV envelopes. Finally, this method based on a chemically synthesized peptide may represent a convenient and versatile tool for protein purification compatible far scale-up in both academic and pharmaceutical researches.
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Affiliation(s)
- Grégoire Martin
- CEA, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, Bât 152, Gif sur Yvette, F-91191, France
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Szmacinski H, Lakowicz JR. Depolarization of surface-enhanced fluorescence: an approach to fluorescence polarization assays. Anal Chem 2008; 80:6260-6. [PMID: 18627176 PMCID: PMC2737419 DOI: 10.1021/ac8003055] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Localized surface plasmons of metallic particles of subwavelength sizes strongly modify the spectral properties of nearby fluorophores. The enhanced radiative decay rate leads to high fluorescence efficiencies and decreased fluorescence lifetimes. In this report we show that metal-enhanced fluorescence generated by the presence of the silver islands on the glass substrate displays high depolarization. Intensities, lifetimes, and emission anisotropies of several fluorophore protein conjugates have been studied in the absence and presence of metallic nanostructures. Despite highly decreased lifetimes of about 10-fold and immobilization of conjugates on the solid substrate, the observed emission anisotropies for all fluorophores on the metal-enhanced substrate decreased 300-500% compared to that in solution. This observation implies a new generation of fluorescence polarization immunoassays with broad applications because of no restrictions to the lifetime of the probe and the size of labeled biomolecules. The changes in polarization are due to binding that occur on the bioactive surface localized near the metal particles.
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Affiliation(s)
- Henryk Szmacinski
- Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland Baltimore, 725 West Lombard Street, Baltimore, Maryland 21201, USA.
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Deng SL, Baglin I, Nour M, Flekhter O, Vita C, Cavé C. Synthesis of Ursolic Phosphonate Derivatives as Potential Anti-HIV Agents. PHOSPHORUS SULFUR 2007. [DOI: 10.1080/10426500601088838] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Sheng-Lou Deng
- a Unité de Molécules d'Intérêt Biologique , UFR de Pharmacie, Dijon , France
| | - Isabelle Baglin
- a Unité de Molécules d'Intérêt Biologique , UFR de Pharmacie, Dijon , France
| | - Mohammed Nour
- a Unité de Molécules d'Intérêt Biologique , UFR de Pharmacie, Dijon , France
| | - Oxana Flekhter
- b Institute of Organic Chemistry , Ufa Scientific Center of the Russian Academy of Science, Ufa , Russia
| | - Claudio Vita
- c Department of Protein Engineering and Research , Centre d'Etude Atomique, Saclay , France
| | - Christian Cavé
- d UMR CNRS BioCis 8076, Faculté de Pharmacie , Châtenay-Malabry , France
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Kong R, Tan JJ, Ma XH, Chen WZ, Wang CX. Prediction of the binding mode between BMS-378806 and HIV-1 gp120 by docking and molecular dynamics simulation. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2006; 1764:766-72. [PMID: 16455315 DOI: 10.1016/j.bbapap.2005.12.017] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2005] [Revised: 12/07/2005] [Accepted: 12/08/2005] [Indexed: 11/20/2022]
Abstract
BMS-378806 is a newly discovered small molecule that effectively blocks the binding of CD4 with gp120. The binding mode of this kind of inhibitor remains unknown. In this paper, AutoDock 3.0 in conjunction with molecular dynamics simulation, accommodating the receptor's flexibility, was used to explore the binding mode between BMS-378806 and gp120. Two structures, Mode I and Mode II, with the lowest docking energy were selected as different representative binding modes. The analysis of the results from the molecular dynamics simulation indicated that the binding of BMS-348806 in Mode II is more stable. The average structure of Mode II was analyzed and compared with the experimental data. The conclusion was that BMS-378806 inserts the azaindole ring deeply into the PHE43 cavity and makes contact with a number of residues in the cavity, on the cavity and near the cavity. This study benefits the understanding of the mechanism of this kind of inhibitor and may provide useful information for rational drug design.
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Affiliation(s)
- Ren Kong
- College of Life Sciences and Bioengineering, Beijing University of Technology, Beijing 100022, China
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