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Talledge N, Yang H, Shi K, Coray R, Yu G, Arndt WG, Meng S, Baxter GC, Mendonça LM, Castaño-Díez D, Aihara H, Mansky LM, Zhang W. HIV-2 Immature Particle Morphology Provides Insights into Gag Lattice Stability and Virus Maturation. J Mol Biol 2023; 435:168143. [PMID: 37150290 PMCID: PMC10524356 DOI: 10.1016/j.jmb.2023.168143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 05/01/2023] [Accepted: 05/01/2023] [Indexed: 05/09/2023]
Abstract
Retrovirus immature particle morphology consists of a membrane enclosed, pleomorphic, spherical and incomplete lattice of Gag hexamers. Previously, we demonstrated that human immunodeficiency virus type 2 (HIV-2) immature particles possess a distinct and extensive Gag lattice morphology. To better understand the nature of the continuously curved hexagonal Gag lattice, we have used the single particle cryo-electron microscopy method to determine the HIV-2 Gag lattice structure for immature virions. The reconstruction map at 5.5 Å resolution revealed a stable, wineglass-shaped Gag hexamer structure with structural features consistent with other lentiviral immature Gag lattice structures. Cryo-electron tomography provided evidence for nearly complete ordered Gag lattice structures in HIV-2 immature particles. We also solved a 1.98 Å resolution crystal structure of the carboxyl-terminal domain (CTD) of the HIV-2 capsid (CA) protein that identified a structured helix 12 supported via an interaction of helix 10 in the absence of the SP1 region of Gag. Residues at the helix 10-12 interface proved critical in maintaining HIV-2 particle release and infectivity. Taken together, our findings provide the first 3D organization of HIV-2 immature Gag lattice and important insights into both HIV Gag lattice stabilization and virus maturation.
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Affiliation(s)
- Nathaniel Talledge
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Masonic Cancer Center, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA. https://twitter.com/BioChemTalledge
| | - Huixin Yang
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Comparative Molecular Biosciences Graduate Program, University of Minnesota - Twin Cities, St. Paul, MN 55108, USA
| | - Ke Shi
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA
| | - Raffaele Coray
- BioEM Lab, Biozentrum, University of Basel - Basel, Switzerland
| | - Guichuan Yu
- Minnesota Supercomputing Institute, Office of the Vice President for Research, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Characterization Facility, College of Sciences and Engineering, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA
| | - William G Arndt
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Biochemistry, Molecular Biology and Biophysics Graduate Program, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA
| | - Shuyu Meng
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Molecular Pharmacology and Therapeutics Graduate Program, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA
| | - Gloria C Baxter
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Masonic Cancer Center, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Molecular, Cellular, Developmental Biology, and Genetics Graduate Program, University of Minnesota - Twin Cities, USA
| | - Luiza M Mendonça
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Biochemistry, Molecular Biology and Biophysics Graduate Program, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA
| | | | - Hideki Aihara
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Biochemistry, Molecular Biology and Biophysics Graduate Program, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA
| | - Louis M Mansky
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Masonic Cancer Center, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Comparative Molecular Biosciences Graduate Program, University of Minnesota - Twin Cities, St. Paul, MN 55108, USA; Biochemistry, Molecular Biology and Biophysics Graduate Program, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Molecular Pharmacology and Therapeutics Graduate Program, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA.
| | - Wei Zhang
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Masonic Cancer Center, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA; Characterization Facility, College of Sciences and Engineering, University of Minnesota - Twin Cities, Minneapolis, MN 55455, USA.
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2
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Moranguinho I, Taveira N, Bártolo I. Antiretroviral Treatment of HIV-2 Infection: Available Drugs, Resistance Pathways, and Promising New Compounds. Int J Mol Sci 2023; 24:ijms24065905. [PMID: 36982978 PMCID: PMC10053740 DOI: 10.3390/ijms24065905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 03/08/2023] [Accepted: 03/17/2023] [Indexed: 03/30/2023] Open
Abstract
Currently, it is estimated that 1-2 million people worldwide are infected with HIV-2, accounting for 3-5% of the global burden of HIV. The course of HIV-2 infection is longer compared to HIV-1 infection, but without effective antiretroviral therapy (ART), a substantial proportion of infected patients will progress to AIDS and die. Antiretroviral drugs in clinical use were designed for HIV-1 and, unfortunately, some do not work as well, or do not work at all, for HIV-2. This is the case for non-nucleoside reverse transcriptase inhibitors (NNRTIs), the fusion inhibitor enfuvirtide (T-20), most protease inhibitors (PIs), the attachment inhibitor fostemsavir and most broadly neutralizing antibodies. Integrase inhibitors work well against HIV-2 and are included in first-line therapeutic regimens for HIV-2-infected patients. However, rapid emergence of drug resistance and cross-resistance within each drug class dramatically reduces second-line treatment options. New drugs are needed to treat infection with drug-resistant isolates. Here, we review the therapeutic armamentarium available to treat HIV-2-infected patients, as well as promising drugs in development. We also review HIV-2 drug resistance mutations and resistance pathways that develop in HIV-2-infected patients under treatment.
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Affiliation(s)
- Inês Moranguinho
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, 1649-019 Lisboa, Portugal
| | - Nuno Taveira
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, 1649-019 Lisboa, Portugal
- Centro de Investigação Interdisciplinar Egas Moniz (CiiEM), Instituto Superior de Ciências da Saúde Egas Moniz, 2829-511 Caparica, Portugal
| | - Inês Bártolo
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, 1649-019 Lisboa, Portugal
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3
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Rösner HI, Caldarini M, Potel G, Malmodin D, Vanoni MA, Aliverti A, Broglia RA, Kragelund BB, Tiana G. The denatured state of HIV-1 protease under native conditions. Proteins 2021; 90:96-109. [PMID: 34312913 PMCID: PMC9290662 DOI: 10.1002/prot.26189] [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: 06/10/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 12/01/2022]
Abstract
The denatured state of several proteins has been shown to display transient structures that are relevant for folding, stability, and aggregation. To detect them by nuclear magnetic resonance (NMR) spectroscopy, the denatured state must be stabilized by chemical agents or changes in temperature. This makes the environment different from that experienced in biologically relevant processes. Using high‐resolution heteronuclear NMR spectroscopy, we have characterized several denatured states of a monomeric variant of HIV‐1 protease, which is natively structured in water, induced by different concentrations of urea, guanidinium chloride, and acetic acid. We have extrapolated the chemical shifts and the relaxation parameters to the denaturant‐free denatured state at native conditions, showing that they converge to the same values. Subsequently, we characterized the conformational properties of this biologically relevant denatured state under native conditions by advanced molecular dynamics simulations and validated the results by comparison to experimental data. We show that the denatured state of HIV‐1 protease under native conditions displays rich patterns of transient native and non‐native structures, which could be of relevance to its guidance through a complex folding process.
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Affiliation(s)
- Heike I Rösner
- BRIC, University of Copenhagen, Copenhagen N, Denmark.,Structural Biology and NMR Laboratory (SBiNlab), Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Martina Caldarini
- Department of Physics, Università degli Studi di Milano and INFN, Milan, Italy
| | - Gregory Potel
- Lawrence Livermore National Laboratory, Livermore, California, USA
| | - Daniel Malmodin
- Structural Biology and NMR Laboratory (SBiNlab), Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Maria A Vanoni
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy
| | | | - Ricardo A Broglia
- Department of Physics, Università degli Studi di Milano and INFN, Milan, Italy.,Niels Bohr Institutet, University of Copenhagen, Copenhagen Ø, Denmark
| | - Birthe B Kragelund
- Structural Biology and NMR Laboratory (SBiNlab), Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Guido Tiana
- Department of Physics, Università degli Studi di Milano and INFN, Milan, Italy.,Center for Complexity and Biosystems, Università degli Studi di Milano, Milan, Italy
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4
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Agniswamy J, Kneller DW, Brothers R, Wang YF, Harrison RW, Weber IT. Highly Drug-Resistant HIV-1 Protease Mutant PRS17 Shows Enhanced Binding to Substrate Analogues. ACS OMEGA 2019; 4:8707-8719. [PMID: 31172041 PMCID: PMC6545544 DOI: 10.1021/acsomega.9b00683] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 05/07/2019] [Indexed: 05/24/2023]
Abstract
We report the structural analysis of highly drug-resistant human immunodeficiency virus protease (PR) variant PRS17, rationally selected by machine learning, in complex with substrate analogues. Crystal structures were solved of inhibitor-free inactive PRS17-D25N, wild-type PR/CA-p2 complex, and PRS17 in complex with substrate analogues, CA-p2 and p2-NC. Peptide analogues p2-NC and CA-p2 exhibit inhibition constants of 514 and 22 nM, respectively, for PRS17 or approximately 3-fold better than for PR. CA-p2 is a better inhibitor of PRS17 than are clinical inhibitors (K i = 50-8390 nM) except for amprenavir (K i = 11 nM). G48V resistance mutation induces curled flap tips in PRS17-D25N structure. The inner P2-P2' residues of substrate analogues in PRS17 complexes maintain similar conformations to those of wild-type complex, while significant conformational changes are observed in the peripheral residues P3, P4' of CA-p2 and P3, P4, and P3' of p2-NC. The loss of β-branched side chain by V82S mutation initiates a shift in 80's loop and reshapes the S3/S3' subsite, which enhances substrate binding with new hydrogen bonds and van der Waals interactions that are absent in the wild-type structures. The steric hindrance caused by G48V mutation in the flap of PRS17 contributes to altered binding interactions of P3 Arg, P4' norleucine of CA-p2, and P4 and P3' of p2-NC with the addition of new hydrogen bonds and van der Waals contacts. The enhanced interaction of PRS17 with substrate analogues agrees with their relative inhibition, suggesting that this mutant improves substrate binding while decreasing affinity for clinical inhibitors.
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Affiliation(s)
- Johnson Agniswamy
- Department
of Biology, Georgia State University, P.O. Box 4010, Atlanta, Georgia 30302, United
States
| | - Daniel W. Kneller
- Department
of Biology, Georgia State University, P.O. Box 4010, Atlanta, Georgia 30302, United
States
| | - Rowan Brothers
- Department
of Chemistry, Georgia State University, P.O. Box 3965, Atlanta, Georgia 30302, United
States
| | - Yuan-Fang Wang
- Department
of Biology, Georgia State University, P.O. Box 4010, Atlanta, Georgia 30302, United
States
| | - Robert W. Harrison
- Department
of Computer Science, Georgia State University, P.O. Box 5060, Atlanta, Georgia 30302, United
States
| | - Irene T. Weber
- Department
of Biology, Georgia State University, P.O. Box 4010, Atlanta, Georgia 30302, United
States
- Department
of Chemistry, Georgia State University, P.O. Box 3965, Atlanta, Georgia 30302, United
States
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5
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Miller Jenkins LM, Paine EL, Deshmukh L, Nikolayevskiy H, Lyons GC, Scerba MT, Rosenker KG, Luecke HF, Louis JM, Chertova E, Gorelick RJ, Ott DE, Clore GM, Appella DH. Inhibition of HIV Maturation via Selective Unfolding and Cross-Linking of Gag Polyprotein by a Mercaptobenzamide Acetylator. J Am Chem Soc 2019; 141:8327-8338. [PMID: 31042030 PMCID: PMC8496520 DOI: 10.1021/jacs.9b02743] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
For HIV to become infectious, any new virion produced from an infected cell must undergo a maturation process that involves the assembly of viral polyproteins Gag and Gag-Pol at the membrane surface. The self-assembly of these viral proteins drives formation of a new viral particle as well as the activation of HIV protease, which is needed to cleave the polyproteins so that the final core structure of the virus will properly form. Molecules that interfere with HIV maturation will prevent any new virions from infecting additional cells. In this manuscript, we characterize the unique mechanism by which a mercaptobenzamide thioester small molecule (SAMT-247) interferes with HIV maturation via a series of selective acetylations at highly conserved cysteine and lysine residues in Gag and Gag-Pol polyproteins. The results provide the first insights into how acetylation can be utilized to perturb the process of HIV maturation and reveal a new strategy to limit the infectivity of HIV.
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Affiliation(s)
- Lisa M. Miller Jenkins
- Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Elliott L. Paine
- Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Lalit Deshmukh
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, United States
| | - Herman Nikolayevskiy
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, United States
| | - Gaelyn C. Lyons
- Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Michael T. Scerba
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, United States
| | - Kara George Rosenker
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, United States
| | - Hans F. Luecke
- Advanced Mass Spectrometry Core, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, United States
| | - John M. Louis
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, United States
| | - Elena Chertova
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21701, United States
| | - Robert J. Gorelick
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21701, United States
| | - David E. Ott
- AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21701, United States
| | - G. Marius Clore
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, United States
| | - Daniel H. Appella
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892, United States
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6
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Structural studies of antiviral inhibitor with HIV-1 protease bearing drug resistant substitutions of V32I, I47V and V82I. Biochem Biophys Res Commun 2019; 514:974-978. [PMID: 31092330 DOI: 10.1016/j.bbrc.2019.05.064] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 05/07/2019] [Indexed: 12/23/2022]
Abstract
HIV-1 protease inhibitors are effective in HIV/AIDS therapy, although drug resistance is a severe problem. This study examines the effects of four investigational inhibitors against HIV-1 protease with drug resistant mutations of V32I, I47V and V82I (PRTri) that model the inhibitor-binding site of HIV-2 protease. These inhibitors contain diverse chemical modifications on the darunavir scaffold and form new interactions with wild type protease, however, the measured inhibition constants for PRTri mutant range from 17 to 40 nM or significantly worse than picomolar values reported for wild type enzyme. The X-ray crystal structure of PRTri mutant in complex with inhibitor 1 at 1.5 Å resolution shows minor changes in interactions with inhibitor compared with the corresponding wild type PR complex. Instead, the basic amine at P2 of inhibitor together with mutation V82I induces two alternate conformations for the side chain of Arg8 with new interactions with inhibitor and Leu10. Hence, inhibition is influenced by small coordinated changes in hydrophobic interactions.
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7
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Agniswamy J, Louis JM, Roche J, Harrison RW, Weber IT. Structural Studies of a Rationally Selected Multi-Drug Resistant HIV-1 Protease Reveal Synergistic Effect of Distal Mutations on Flap Dynamics. PLoS One 2016; 11:e0168616. [PMID: 27992544 PMCID: PMC5161481 DOI: 10.1371/journal.pone.0168616] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 12/02/2016] [Indexed: 12/20/2022] Open
Abstract
We report structural analysis of HIV protease variant PRS17 which was rationally selected by machine learning to represent wide classes of highly drug-resistant variants. Crystal structures were solved of PRS17 in the inhibitor-free form and in complex with antiviral inhibitor, darunavir. Despite its 17 mutations, PRS17 has only one mutation (V82S) in the inhibitor/substrate binding cavity, yet exhibits high resistance to all clinical inhibitors. PRS17 has none of the major mutations (I47V, I50V, I54ML, L76V and I84V) associated with darunavir resistance, but has 10,000-fold weaker binding affinity relative to the wild type PR. Comparable binding affinity of 8000-fold weaker than PR is seen for drug resistant mutant PR20, which bears 3 mutations associated with major resistance to darunavir (I47V, I54L and I84V). Inhibitor-free PRS17 shows an open flap conformation with a curled tip correlating with G48V flap mutation. NMR studies on inactive PRS17D25N unambiguously confirm that the flaps adopt mainly an open conformation in solution very similar to that in the inhibitor-free crystal structure. In PRS17, the hinge loop cluster of mutations, E35D, M36I and S37D, contributes to the altered flap dynamics by a mechanism similar to that of PR20. An additional K20R mutation anchors an altered conformation of the hinge loop. Flap mutations M46L and G48V in PRS17/DRV complex alter the Phe53 conformation by steric hindrance between the side chains. Unlike the L10F mutation in PR20, L10I in PRS17 does not break the inter-subunit ion pair or diminish the dimer stability, consistent with a very low dimer dissociation constant comparable to that of wild type PR. Distal mutations A71V, L90M and I93L propagate alterations to the catalytic site of PRS17. PRS17 exhibits a molecular mechanism whereby mutations act synergistically to alter the flap dynamics resulting in significantly weaker binding yet maintaining active site contacts with darunavir.
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Affiliation(s)
- Johnson Agniswamy
- Department of Biology, Georgia State University, Atlanta, Georgia, United States of America
| | - John M. Louis
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, DHHS, Bethesda, Maryland, United States of America
| | - Julien Roche
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, DHHS, Bethesda, Maryland, United States of America
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa, United States of America
| | - Robert W. Harrison
- Department of Biology, Georgia State University, Atlanta, Georgia, United States of America
- Department of Computer Science, Georgia State University, Atlanta, Georgia, United States of America
| | - Irene T. Weber
- Department of Biology, Georgia State University, Atlanta, Georgia, United States of America
- Department of Chemistry, Georgia State University, Atlanta, Georgia, United States of America
- * E-mail:
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8
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Park JH, Sayer JM, Aniana A, Yu X, Weber IT, Harrison RW, Louis JM. Binding of Clinical Inhibitors to a Model Precursor of a Rationally Selected Multidrug Resistant HIV-1 Protease Is Significantly Weaker Than That to the Released Mature Enzyme. Biochemistry 2016; 55:2390-400. [PMID: 27039930 DOI: 10.1021/acs.biochem.6b00012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have systematically validated the activity and inhibition of a HIV-1 protease (PR) variant bearing 17 mutations (PR(S17)), selected to represent high resistance by machine learning on genotype-phenotype data. Three of five mutations in PR(S17) correlating with major drug resistance, M46L, G48V, and V82S, and five of 11 natural variations differ from the mutations in two clinically derived extreme mutants, PR20 and PR22 bearing 19 and 22 mutations, respectively. PR(S17), which forms a stable dimer (<10 nM), is ∼10- and 2-fold less efficient in processing the Gag polyprotein than the wild type and PR20, respectively, but maintains the same cleavage order. Isolation of a model precursor of PR(S17) flanked by the 56-amino acid transframe region (TFP-p6pol) at its N-terminus, which is impossible upon expression of an analogous PR20 precursor, allowed systematic comparison of inhibition of TFP-p6pol-PR(S17) and mature PR(S17). Resistance of PR(S17) to eight protease inhibitors (PIs) relative to PR (Ki) increases by 1.5-5 orders of magnitude from 0.01 to 8.4 μM. Amprenavir, darunavir, atazanavir, and lopinavir, the most effective of the eight PIs, inhibit precursor autoprocessing at the p6pol/PR site with IC50 values ranging from ∼7.5 to 60 μM. Thus, this process, crucial for stable dimer formation, shows inhibition ∼200-800-fold weaker than that of the mature PR(S17). TFP/p6pol cleavage, which occurs faster, is inhibited even more weakly by all PIs except darunavir (IC50 = 15 μM); amprenavir shows a 2-fold increase in IC50 (∼15 μM), and atazanavir and lopinavir show increased IC50 values of >42 and >70 μM, respectively.
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Affiliation(s)
- Joon H Park
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services , Bethesda, Maryland 20892, United States
| | - Jane M Sayer
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services , Bethesda, Maryland 20892, United States
| | - Annie Aniana
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services , Bethesda, Maryland 20892, United States
| | | | | | | | - John M Louis
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services , Bethesda, Maryland 20892, United States
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9
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Mahdi M, Szojka Z, Mótyán JA, Tőzsér J. Inhibition Profiling of Retroviral Protease Inhibitors Using an HIV-2 Modular System. Viruses 2015; 7:6152-62. [PMID: 26633459 PMCID: PMC4690855 DOI: 10.3390/v7122931] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 11/11/2015] [Accepted: 11/13/2015] [Indexed: 12/13/2022] Open
Abstract
Retroviral protease inhibitors (PIs) are fundamental pillars in the treatment of HIV infection and acquired immunodeficiency syndrome (AIDS). Currently used PIs are designed against HIV-1, and their effect on HIV-2 is understudied. Using a modular HIV-2 protease cassette system, inhibition profiling assays were carried out for protease inhibitors both in enzymatic and cell culture assays. Moreover, the treatment-associated resistance mutations (I54M, L90M) were introduced into the modular system, and comparative inhibition assays were performed to determine their effect on the susceptibility of the protease. Our results indicate that darunavir, saquinavir, indinavir and lopinavir were very effective HIV-2 protease inhibitors, while tipranavir, nelfinavir and amprenavir showed a decreased efficacy. I54M, L90M double mutation resulted in a significant reduction in the susceptibility to most of the inhibitors with the exception of tipranavir. To our knowledge, this modular system constitutes a novel approach in the field of HIV-2 protease characterization and susceptibility testing.
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Affiliation(s)
- Mohamed Mahdi
- Laboratory of Retroviral Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, H-4010 Debrecen, Hungary.
| | - Zsófia Szojka
- Laboratory of Retroviral Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, H-4010 Debrecen, Hungary.
| | - János András Mótyán
- Laboratory of Retroviral Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, H-4010 Debrecen, Hungary.
| | - József Tőzsér
- Laboratory of Retroviral Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, H-4010 Debrecen, Hungary.
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10
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Louis JM, Deshmukh L, Sayer JM, Aniana A, Clore GM. Mutations Proximal to Sites of Autoproteolysis and the α-Helix That Co-evolve under Drug Pressure Modulate the Autoprocessing and Vitality of HIV-1 Protease. Biochemistry 2015; 54:5414-24. [PMID: 26266692 DOI: 10.1021/acs.biochem.5b00759] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
N-Terminal self-cleavage (autoprocessing) of the HIV-1 protease precursor is crucial for liberating the active dimer. Under drug pressure, evolving mutations are predicted to modulate autoprocessing, and the reduced catalytic activity of the mature protease (PR) is likely compensated by enhanced conformational/dimer stability and reduced susceptibility to self-degradation (autoproteolysis). One such highly evolved, multidrug resistant protease, PR20, bears 19 mutations contiguous to sites of autoproteolysis in retroviral proteases, namely clusters 1-3 comprising residues 30-37, 60-67, and 88-95, respectively, accounting for 11 of the 19 mutations. By systematically replacing corresponding clusters in PR with those of PR20, and vice versa, we assess their influence on the properties mentioned above and observe no strict correlation. A 10-35-fold decrease in the cleavage efficiency of peptide substrates by PR20, relative to PR, is reflected by an only ∼4-fold decrease in the rate of Gag processing with no change in cleavage order. Importantly, optimal N-terminal autoprocessing requires all 19 PR20 mutations as evaluated in vitro using the model precursor TFR-PR20 in which PR is flanked by the transframe region. Substituting PR20 cluster 3 into TFR-PR (TFR-PR(PR20-3)) requires the presence of PR20 cluster 1 and/or 2 for autoprocessing. In accordance, substituting PR clusters 1 and 2 into TFR-PR20 affects the rate of autoprocessing more drastically (>300-fold) compared to that of TFR-PR(PR20-3) because of the cumulative effect of eight noncluster mutations present in TFR-PR20(PR-12). Overall, these studies imply that drug resistance involves a complex synchronized selection of mutations modulating all of the properties mentioned above governing PR regulation and function.
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Affiliation(s)
- John M Louis
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services , Bethesda, Maryland 20892, United States
| | - Lalit Deshmukh
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services , Bethesda, Maryland 20892, United States
| | - Jane M Sayer
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services , Bethesda, Maryland 20892, United States
| | - Annie Aniana
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services , Bethesda, Maryland 20892, United States
| | - G Marius Clore
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services , Bethesda, Maryland 20892, United States
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11
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Potempa M, Nalivaika E, Ragland D, Lee SK, Schiffer CA, Swanstrom R. A Direct Interaction with RNA Dramatically Enhances the Catalytic Activity of the HIV-1 Protease In Vitro. J Mol Biol 2015; 427:2360-78. [PMID: 25986307 DOI: 10.1016/j.jmb.2015.05.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 05/08/2015] [Accepted: 05/08/2015] [Indexed: 01/09/2023]
Abstract
Though the steps of human immunodeficiency virus type 1 (HIV-1) virion maturation are well documented, the mechanisms regulating the proteolysis of the Gag and Gag-Pro-Pol polyproteins by the HIV-1 protease (PR) remain obscure. One proposed mechanism argues that the maturation intermediate p15NC must interact with RNA for efficient cleavage by the PR. We investigated this phenomenon and found that processing of multiple substrates by the HIV-1 PR was enhanced in the presence of RNA. The acceleration of proteolysis occurred independently from the substrate's ability to interact with nucleic acid, indicating that a direct interaction between substrate and RNA is not necessary for enhancement. Gel-shift assays demonstrated the HIV-1 PR is capable of interacting with nucleic acids, suggesting that RNA accelerates processing reactions by interacting with the PR rather than the substrate. All HIV-1 PRs examined have this ability; however, the HIV-2 PR does not interact with RNA and does not exhibit enhanced catalytic activity in the presence of RNA. No specific sequence or structure was required in the RNA for a productive interaction with the HIV-1 PR, which appears to be principally, though not exclusively, driven by electrostatic forces. For a peptide substrate, RNA increased the kinetic efficiency of the HIV-1 PR by an order of magnitude, affecting both turnover rate (k(cat)) and substrate affinity (K(m)). These results suggest that an allosteric binding site exists on the HIV-1 PR and that HIV-1 PR activity during maturation could be regulated in part by the juxtaposition of the enzyme with virion-packaged RNA.
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Affiliation(s)
- Marc Potempa
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Ellen Nalivaika
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Debra Ragland
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Sook-Kyung Lee
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Celia A Schiffer
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Ronald Swanstrom
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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12
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Inhibitor and substrate binding induced stability of HIV-1 protease against sequential dissociation and unfolding revealed by high pressure spectroscopy and kinetics. PLoS One 2015; 10:e0119099. [PMID: 25781460 PMCID: PMC4362767 DOI: 10.1371/journal.pone.0119099] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Accepted: 01/28/2015] [Indexed: 01/10/2023] Open
Abstract
High-pressure methods have become an interesting tool of investigation of structural stability of proteins. They are used to study protein unfolding, but dissociation of oligomeric proteins can be addressed this way, too. HIV-1 protease, although an interesting object of biophysical experiments, has not been studied at high pressure yet. In this study HIV-1 protease is investigated by high pressure (up to 600 MPa) fluorescence spectroscopy of either the inherent tryptophan residues or external 8-anilino-1-naphtalenesulfonic acid at 25°C. A fast concentration-dependent structural transition is detected that corresponds to the dimer-monomer equilibrium. This transition is followed by a slow concentration independent transition that can be assigned to the monomer unfolding. In the presence of a tight-binding inhibitor none of these transitions are observed, which confirms the stabilizing effect of inhibitor. High-pressure enzyme kinetics (up to 350 MPa) also reveals the stabilizing effect of substrate. Unfolding of the protease can thus proceed only from the monomeric state after dimer dissociation and is unfavourable at atmospheric pressure. Dimer-destabilizing effect of high pressure is caused by negative volume change of dimer dissociation of -32.5 mL/mol. It helps us to determine the atmospheric pressure dimerization constant of 0.92 μM. High-pressure methods thus enable the investigation of structural phenomena that are difficult or impossible to measure at atmospheric pressure.
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13
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Zhao H, Caflisch A. Molecular dynamics in drug design. Eur J Med Chem 2015; 91:4-14. [DOI: 10.1016/j.ejmech.2014.08.004] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 07/31/2014] [Accepted: 08/03/2014] [Indexed: 11/30/2022]
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14
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Mahdi M, Matúz K, Tóth F, Tőzsér J. A modular system to evaluate the efficacy of protease inhibitors against HIV-2. PLoS One 2014; 9:e113221. [PMID: 25419967 PMCID: PMC4242608 DOI: 10.1371/journal.pone.0113221] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 10/21/2014] [Indexed: 01/27/2023] Open
Abstract
The human immunodeficiency virus (HIV) protease is a homodimeric aspartyl protease that is crucial for the viral life-cycle, cleaving proviral polyproteins, hence creating mature protein components that are required for the formation of an infectious virus. With diagnostic measures and clinically used protease inhibitors focusing on HIV-1, due to its higher virulence and prevalence, studies of the efficacy of those inhibitors on HIV-2 protease remain widely lacking. Utilizing a wild-type HIV-2 vector backbone and cloning techniques we have developed a cassette system where the efficacy of clinically used protease inhibitors can be studied for various serotypes of HIV-2 protease both in enzymatic and cell culture assays. In our experiments, optimization of the expression protocol led to a relatively stable enzyme, for cell culture assays, the efficiency of transfection and transduction capability of the modified vector was tested and was not found to differ from that of the wild-type, moreover, a 2nd generation protease inhibitor was used to demonstrate the usefulness of the system. The combination of assays performed with our cassette system is expected to provide an accurate measure of the efficacy of currently used; as well as experimental protease inhibitors on HIV-2.
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Affiliation(s)
- Mohamed Mahdi
- Laboratory of Retroviral Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- * E-mail: (MM); (JT)
| | - Krisztina Matúz
- Laboratory of Retroviral Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Ferenc Tóth
- Laboratory of Retroviral Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - József Tőzsér
- Laboratory of Retroviral Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- * E-mail: (MM); (JT)
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15
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Kutálková E, Hrnčiřík J, Ingr M. Pressure induced structural changes and dimer destabilization of HIV-1 protease studied by molecular dynamics simulations. Phys Chem Chem Phys 2014; 16:25906-15. [DOI: 10.1039/c4cp03676j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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Zhang Y, Chang YCE, Louis JM, Wang YF, Harrison RW, Weber IT. Structures of darunavir-resistant HIV-1 protease mutant reveal atypical binding of darunavir to wide open flaps. ACS Chem Biol 2014; 9:1351-8. [PMID: 24738918 PMCID: PMC4076034 DOI: 10.1021/cb4008875] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
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The molecular basis for high resistance
to clinical inhibitors
of HIV-1 protease (PR) was examined for the variant designated PRP51 that was selected for resistance to darunavir (DRV). High
resolution crystal structures of PRP51 with the active
site D25N mutation revealed a ligand-free form and an inhibitor-bound
form showing a unique binding site and orientation for DRV. This inactivating
mutation is known to increase the dimer dissociation constant and
decrease DRV affinity of PR. The PRP51-D25N dimers
were in the open conformation with widely separated flaps, as reported
for other highly resistant variants. PRP51-D25N dimer
bound two DRV molecules and showed larger separation of 8.7 Å
between the closest atoms of the two flaps compared with 4.4 Å
for the ligand-free structure of this mutant. The ligand-free structure,
however, lacked van der Waals contacts between Ile50 and Pro81′
from the other subunit in the dimer, unlike the majority of PR structures.
DRV is bound inside the active site cavity; however, the inhibitor
is oriented almost perpendicular to its typical position and exhibits
only 2 direct hydrogen bond and two water-mediated interactions with
atoms of PRP51-D25N compared with 11 hydrogen bond
interactions seen for DRV bound in the typical position in wild-type
enzyme. The atypical location of DRV may provide opportunities for
design of novel inhibitors targeting the open conformation of PR drug-resistant
mutants.
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Affiliation(s)
| | | | - John M. Louis
- Laboratory
of Chemical Physics, National Institute of Diabetes and Digestive
and Kidney Diseases, National Institutes of Health, DHHS, Bethesda, Maryland 20892-0520, United States
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17
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Louis JM, Tözsér J, Roche J, Matúz K, Aniana A, Sayer JM. Enhanced stability of monomer fold correlates with extreme drug resistance of HIV-1 protease. Biochemistry 2013; 52:7678-88. [PMID: 24079831 PMCID: PMC3888107 DOI: 10.1021/bi400962r] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
During treatment, mutations in HIV-1 protease (PR) are selected rapidly that confer resistance by decreasing affinity to clinical protease inhibitors (PIs). As these unique drug resistance mutations can compromise the fitness of the virus to replicate, mutations that restore conformational stability and activity while retaining drug resistance are selected on further evolution. Here we identify several compensating mechanisms by which an extreme drug-resistant mutant bearing 20 mutations (PR20) with >5-fold increased Kd and >4000-fold decreased affinity to the PI darunavir functions. (1) PR20 cleaves, albeit poorly, Gag polyprotein substrates essential for viral maturation. (2) PR20 dimer, which exhibits distinctly enhanced thermal stability, has highly attenuated autoproteolysis, thus likely prolonging its lifetime in vivo. (3) The enhanced stability of PR20 results from stabilization of the monomer fold. Both monomeric PR20(T26A) and dimeric PR20 exhibit Tm values 6-7.5 °C higher than those for their PR counterparts. Two specific mutations in PR20, L33F and L63P at sites of autoproteolysis, increase the Tm of monomeric PR(T26A) by ~8 °C, similar to PR20(T26A). However, without other compensatory mutations as seen in PR20, L33F and L63P substitutions, together, neither restrict autoproteolysis nor significantly reduce binding affinity to darunavir. To determine whether dimer stability contributes to binding affinity for inhibitors, we examined single-chain dimers of PR and PR(D25N) in which the corresponding identical monomer units were covalently linked by GGSSG sequence. Linking of the subunits did not appreciably change the ΔTm on inhibitor binding; thus stabilization by tethering appears to have little direct effect on enhancing inhibitor affinity.
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Affiliation(s)
- John M. Louis
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, DHHS, Bethesda, Maryland 20892
| | - József Tözsér
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary H-4012
| | - Julien Roche
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, DHHS, Bethesda, Maryland 20892
| | - Krisztina Matúz
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary H-4012
| | - Annie Aniana
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, DHHS, Bethesda, Maryland 20892
| | - Jane M. Sayer
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, DHHS, Bethesda, Maryland 20892
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18
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Sayer JM, Aniana A, Louis JM. Mechanism of dissociative inhibition of HIV protease and its autoprocessing from a precursor. J Mol Biol 2012; 422:230-44. [PMID: 22659320 PMCID: PMC3418415 DOI: 10.1016/j.jmb.2012.05.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 05/15/2012] [Accepted: 05/15/2012] [Indexed: 11/17/2022]
Abstract
Dimerization is indispensible for release of the human immunodeficiency virus protease (PR) from its precursor (Gag-Pol) and ensuing mature-like catalytic activity that is crucial for virus maturation. We show that a single-chain Fv fragment (scFv) of a previously reported monoclonal antibody (mAb1696), which recognizes the N-terminus of PR, dissociates a dimeric mature D25N PR mutant with an enhanced dimer dissociation constant (K(d)) in the sub-micromolar range to form predominantly a monomer-scFv complex at a 1:1 ratio, along with small (5-10%) amounts of a dimer-scFv complex. Enzyme kinetics indicate a mixed mechanism of inhibition of the wild-type PR, which exhibits a K(d)<10nM, with effects both on K(m) and k(cat) at an scFv-to-PR ratio of 10:1. ScFv binds to the N-terminal peptide P(1)QITLW(6) of PR and to PR monomers with dissociation constants of ≤30 nM and ~100 nM, respectively. Consistent with an ~400-fold increase in the dissociation of the antibody (K(Ab)) on even addition of an acetyl group to P(1) of the peptide, the antibody fails to inhibit N-terminal autoprocessing of the PR from a model precursor (at ~5 μM). However, subsequent to this cleavage, it sequesters the PR, thus blocking autoprocessing at its C-terminus. A second monoclonal antibody [PRM1 (human monoclonal antibody to PR)], which recognizes part of the flap region (residues 41-47) of the mature PR and its precursor, does not inhibit autoprocessing and ensuing catalytic activity. However, its failure to recognize drug-resistant clinical mutants of PR may be beneficial to monitor the selection of mutations in this region under drug pressure.
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Affiliation(s)
| | | | - John M. Louis
- Corresponding author: John M. Louis, Building 5, Room B2-29, LCP, NIDDK, NIH, Bethesda, MD 20892-0520, Tel. 301 594-3122; Fax. 301 480-4001;
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19
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Huang D, Caflisch A. How Does Darunavir Prevent HIV-1 Protease Dimerization? J Chem Theory Comput 2012; 8:1786-94. [PMID: 26593669 DOI: 10.1021/ct300032r] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The drug Darunavir (DRV) is a potent inhibitor of HIV-1 protease (PR), a homodimeric essential enzyme of the AIDS virus. Recent experimental data suggest that DRV is able to prevent dimerization of HIV-1 PR, which, together with its high affinity for the mature enzyme, has been linked to the high genetic barrier to the development of viral resistance. The mechanism of dimerization inhibition and the binding mode(s) of DRV to monomeric HIV-1 PR are unknown. Here, multiple molecular dynamics simulations with explicit solvent (for a total of 11 μs with the CHARMM force field and 1 μs with the Amber force field) show that the monomer of HIV-1 PR is structurally stable and reveal a major binding mode of DRV. This binding mode is stabilized by favorable interactions between the apolar groups of DRV and the hydrophobic residues Ile32, Ile47, Ile50, Ile54, Pro79, Val82, and Ile84. The binding mode to monomeric HIV-1 PR identified by molecular dynamics is different from the two binding modes observed in the crystal structure of the complex with dimeric HIV-1 PR. As an example, there are no interactions between DRV and the catalytic Asp25 in the binding mode to monomeric HIV-1 PR revelead by the simulations. In contrast, the simulations show extensive and stable interactions between DRV and the flap (residues 46-55), which are likely to sterically hinder the formation of the flap interface as observed in the dimeric structure. Which of the two mechanisms of inhibition (dimerization inhibition by association with the flap or binding to the active site of the mature enzyme) dominates might depend on the HIV-1 PR mutations, and it is likely that dimerization inhibition is predominant for multiple mutations at the active site in multidrug resistant strains.
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Affiliation(s)
- Danzhi Huang
- Department of Biochemistry, University of Zürich , Winterthurerstrasse 190 CH-8057 Zürich, Switzerland
| | - Amedeo Caflisch
- Department of Biochemistry, University of Zürich , Winterthurerstrasse 190 CH-8057 Zürich, Switzerland
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20
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Tie Y, Wang YF, Boross PI, Chiu TY, Ghosh AK, Tozser J, Louis JM, Harrison RW, Weber IT. Critical differences in HIV-1 and HIV-2 protease specificity for clinical inhibitors. Protein Sci 2012; 21:339-50. [PMID: 22238126 DOI: 10.1002/pro.2019] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Revised: 12/13/2011] [Accepted: 12/13/2011] [Indexed: 11/12/2022]
Abstract
Clinical inhibitor amprenavir (APV) is less effective on HIV-2 protease (PR₂) than on HIV-1 protease (PR₁). We solved the crystal structure of PR₂ with APV at 1.5 Å resolution to identify structural changes associated with the lowered inhibition. Furthermore, we analyzed the PR₁ mutant (PR(1M) ) with substitutions V32I, I47V, and V82I that mimic the inhibitor binding site of PR₂. PR(1M) more closely resembled PR₂ than PR₁ in catalytic efficiency on four substrate peptides and inhibition by APV, whereas few differences were seen for two other substrates and inhibition by saquinavir (SQV) and darunavir (DRV). High resolution crystal structures of PR(1M) with APV, DRV, and SQV were compared with available PR₁ and PR₂ complexes. Val/Ile32 and Ile/Val47 showed compensating interactions with SQV in PR(1M) and PR₁, however, Ile82 interacted with a second SQV bound in an extension of the active site cavity of PR(1M). Residues 32 and 82 maintained similar interactions with DRV and APV in all the enzymes, whereas Val47 and Ile47 had opposing effects in the two subunits. Significantly diminished interactions were seen for the aniline of APV bound in PR₁ (M) and PR₂ relative to the strong hydrogen bonds observed in PR₁, consistent with 15- and 19-fold weaker inhibition, respectively. Overall, PR(1M) partially replicates the specificity of PR₂ and gives insight into drug resistant mutations at residues 32, 47, and 82. Moreover, this analysis provides a structural explanation for the weaker antiviral effects of APV on HIV-2.
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Affiliation(s)
- Yunfeng Tie
- Department of Biology, Georgia State University, Atlanta, Georgia 30303, USA
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21
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Sayer JM, Agniswamy J, Weber IT, Louis JM. Autocatalytic maturation, physical/chemical properties, and crystal structure of group N HIV-1 protease: relevance to drug resistance. Protein Sci 2011; 19:2055-72. [PMID: 20737578 DOI: 10.1002/pro.486] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The mature protease from Group N human immunodeficiency virus Type 1 (HIV-1) (PR1(N)) differs in 20 amino acids from the extensively studied Group M protease (PR1(M)) at positions corresponding to minor drug-resistance mutations (DRMs). The first crystal structure (1.09 Å resolution) of PR1(N) with the clinical inhibitor darunavir (DRV) reveals the same overall structure as PR1(M), but with a slightly larger inhibitor-binding cavity. Changes in the 10s loop and the flap hinge propagate to shift one flap away from the inhibitor, whereas L89F and substitutions in the 60s loop perturb inhibitor-binding residues 29-32. However, kinetic parameters of PR1(N) closely resemble those of PR1(M), and calorimetric results are consistent with similar binding affinities for DRV and two other clinical PIs, suggesting that minor DRMs coevolve to compensate for the detrimental effects of drug-specific major DRMs. A miniprecursor (TFR 1-61-PR1(N)) comprising the transframe region (TFR) fused to the N-terminus of PR1(N) undergoes autocatalytic cleavage at the TFR/PR1(N) site concomitant with the appearance of catalytic activity characteristic of the dimeric, mature enzyme. This cleavage is inhibited at an equimolar ratio of precursor to DRV (∼6 μM), which partially stabilizes the precursor dimer from a monomer. However, cleavage at L34/W35 within the TFR, which precedes the TFR 1-61/PR1(N) cleavage at pH ≤ 5, is only partially inhibited. Favorable properties of PR1(N) relative to PR1(M) include its suitability for column fractionation by size under native conditions and >10-fold higher dimer dissociation constant (150 nM). Exploiting these properties may facilitate testing of potential dimerization inhibitors that perturb early precursor processing steps.
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Affiliation(s)
- Jane M Sayer
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, DHHS, Bethesda, Maryland 20892-0520, USA
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