1
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Antolini C, Jacoby DJ, Tiano SM, Otolski CJ, Doumy G, March AM, Walko DA, Goodwill JE, Hayes D. Ten-Fold Solvent Kinetic Isotope Effect for the Nonradiative Relaxation of the Aqueous Ferrate(VI) Ion. J Phys Chem A 2023. [PMID: 38029389 DOI: 10.1021/acs.jpca.3c06042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2023]
Abstract
Hypervalent iron intermediates have been invoked in the catalytic cycles of many metalloproteins, and thus, it is crucial to understand how the coupling between such species and their environment can impact their chemical and physical properties in such contexts. In this work, we take advantage of the solvent kinetic isotope effect (SKIE) to gain insight into the nonradiative deactivation of electronic excited states of the aqueous ferrate(VI) ion. We observe an exceptionally large SKIE of 9.7 for the nanosecond-scale relaxation of the lowest energy triplet ligand field state to the ground state. Proton inventory studies demonstrate that a single solvent O-H bond is coupled to the ion during deactivation, likely due to the sparse vibrational structure of ferrate(VI). Such a mechanism is consistent with that reported for the deactivation of f-f excited states of aqueous trivalent lanthanides, which exhibit comparably large SKIE values. This phenomenon is ascribed entirely to dissipation of energy into a higher overtone of a solvent acceptor mode, as any impact on the apparent relaxation rate due to a change in solvent viscosity is negligible.
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Affiliation(s)
- Cali Antolini
- Department of Chemistry, University of Rhode Island, Kingston, Rhode Island 02881, United States
| | - Danielle J Jacoby
- Department of Chemistry, University of Rhode Island, Kingston, Rhode Island 02881, United States
| | - Sophia M Tiano
- Department of Chemistry, University of Rhode Island, Kingston, Rhode Island 02881, United States
| | - Christopher J Otolski
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Gilles Doumy
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Anne Marie March
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Donald A Walko
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Joseph E Goodwill
- Department of Civil and Environmental Engineering, University of Rhode Island, Kingston, Rhode Island 02881, United States
| | - Dugan Hayes
- Department of Chemistry, University of Rhode Island, Kingston, Rhode Island 02881, United States
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2
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Petrillo N, Dinh K, Vogt KA, Ma S. Catalytic Mechanism of Human T-Cell Leukemia Virus Type 1 Protease Investigated by Combined QM/MM Molecular Dynamics Simulations. J Chem Inf Model 2023. [PMID: 37289654 DOI: 10.1021/acs.jcim.3c00440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Combined quantum mechanical and molecular mechanical (QM/MM) molecular dynamics simulations were performed to investigate the catalytic mechanism of human T-cell leukemia virus type 1 (HTLV-1) protease, a retroviral aspartic protease that is a potential therapeutic target for curing HTLV-1-associated diseases. To elucidate the proteolytic cleavage mechanism, we determined the two-dimensional free energy surfaces of the HTLV-1 protease-catalyzed reactions through various possible pathways. The free energy simulations suggest that the catalytic reactions of the HTLV-1 protease occur in the following sequential steps: (1) a proton is transferred from the lytic water to Asp32', followed by the nucleophilic addition of the resulting hydroxyl to the carbonyl carbon of the scissile bond, forming a tetrahedral oxyanion intermediate, and (2) a proton is transferred from Asp32 to the peptide nitrogen of the scissile bond, leading to the spontaneous breakage of the scissile bond. The rate-limiting step of this catalytic process is the proton transfer from Asp32 to the peptide nitrogen of the scissile bond, with a free energy of activation of 21.1 kcal/mol. This free energy barrier is close to the experimentally determined free energy of activation (16.3 kcal/mol) calculated from the measured catalytic rate constant (kcat). This mechanistic study provides detailed dynamic and structural information that will facilitate the design of mechanism-based inhibitors for the treatment of HTLV-1-associated diseases.
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Affiliation(s)
- Natalie Petrillo
- Department of Chemistry, Jess and Mildred Fisher College of Science and Mathematics, Towson University, 8000 York Road, Towson, Maryland 21252, United States
| | - Kim Dinh
- Department of Chemistry, Jess and Mildred Fisher College of Science and Mathematics, Towson University, 8000 York Road, Towson, Maryland 21252, United States
| | - Kimberly A Vogt
- Department of Chemistry, Jess and Mildred Fisher College of Science and Mathematics, Towson University, 8000 York Road, Towson, Maryland 21252, United States
| | - Shuhua Ma
- Department of Chemistry, Jess and Mildred Fisher College of Science and Mathematics, Towson University, 8000 York Road, Towson, Maryland 21252, United States
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3
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Coimbra JTS, Neves RPP, Cunha AV, Ramos MJ, Fernandes PA. Different Enzyme Conformations Induce Different Mechanistic Traits in HIV‐1 Protease. Chemistry 2022; 28:e202201066. [DOI: 10.1002/chem.202201066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Indexed: 11/06/2022]
Affiliation(s)
- João T. S. Coimbra
- LAQV/REQUIMTE Departamento de Química e Bioquímica Faculdade de Ciências Universidade do Porto Rua do Campo Alegre, s/n 4169-007 Porto Portugal
| | - Rui P. P. Neves
- LAQV/REQUIMTE Departamento de Química e Bioquímica Faculdade de Ciências Universidade do Porto Rua do Campo Alegre, s/n 4169-007 Porto Portugal
| | - Ana V. Cunha
- Scientific Computing Group Oak Ridge National Laboratory 1 Bethel Valley Rd 37831-6373 Oak Ridge TN USA
- Presnt address: Department of Chemistry University of Antwerp Groenenborgerlaan 171 2020 Antwerp Belgium
| | - Maria J. Ramos
- LAQV/REQUIMTE Departamento de Química e Bioquímica Faculdade de Ciências Universidade do Porto Rua do Campo Alegre, s/n 4169-007 Porto Portugal
| | - Pedro A. Fernandes
- LAQV/REQUIMTE Departamento de Química e Bioquímica Faculdade de Ciências Universidade do Porto Rua do Campo Alegre, s/n 4169-007 Porto Portugal
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4
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Neela YI, Guruprasad L. Structures and energetics of darunavir and active site amino acids of native and mutant HIV–1 protease: a computational study. Struct Chem 2021. [DOI: 10.1007/s11224-021-01852-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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5
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Sanusi ZK, Lawal MM, Gupta PL, Govender T, Baijnath S, Naicker T, Maguire GEM, Honarparvar B, Roitberg AE, Kruger HG. Exploring the concerted mechanistic pathway for HIV-1 PR-substrate revealed by umbrella sampling simulation. J Biomol Struct Dyn 2020; 40:1736-1747. [PMID: 33073714 DOI: 10.1080/07391102.2020.1832578] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
HIV-1 protease (HIV-1 PR) is an essential enzyme for the replication process of its virus, and therefore considered an important target for the development of drugs against the acquired immunodeficiency syndrome (AIDS). Our previous study shows that the catalytic mechanism of subtype B/C-SA HIV-1 PR follows a one-step concerted acyclic hydrolysis reaction process using a two-layered ONIOM B3LYP/6-31++G(d,p) method. This present work is aimed at exploring the proposed mechanism of the proteolysis catalyzed by HIV-1 PR and to ensure our proposed mechanism is not an artefact of a single theoretical technique. Hence, we present umbrella sampling method that is suitable for calculating potential mean force (PMF) for non-covalent ligand/substrate-enzyme association/dissociation interactions which provide thermodynamic details for molecular recognition. The free activation energy results were computed in terms of PMF analysis within the hybrid QM(DFTB)/MM approach. The theoretical findings suggest that the proposed mechanism corresponds in principle with experimental data. Given our observations, we suggest that the QM/MM MD method can be used as a reliable computational technique to rationalize lead compounds against specific targets such as the HIV-1 protease.
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Affiliation(s)
- Zainab K Sanusi
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Monsurat M Lawal
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Pancham Lal Gupta
- Department of Chemistry, University of Florida, Gainesville, Florida, USA
| | | | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Tricia Naicker
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Glenn E M Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa.,School of Chemistry and Physics, University of KwaZulu-Natal, Durban, South Africa
| | - Bahareh Honarparvar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Adrian E Roitberg
- Department of Chemistry, University of Florida, Gainesville, Florida, USA
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
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6
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Lawal MM, Sanusi ZK, Govender T, Maguire GE, Honarparvar B, Kruger HG. From Recognition to Reaction Mechanism: An Overview on the Interactions between HIV-1 Protease and its Natural Targets. Curr Med Chem 2020; 27:2514-2549. [DOI: 10.2174/0929867325666181113122900] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 11/04/2018] [Accepted: 11/07/2018] [Indexed: 12/28/2022]
Abstract
Current investigations on the Human Immunodeficiency Virus Protease (HIV-1
PR) as a druggable target towards the treatment of AIDS require an update to facilitate further
development of promising inhibitors with improved inhibitory activities. For the past two
decades, up to 100 scholarly reports appeared annually on the inhibition and catalytic mechanism
of HIV-1 PR. A fundamental literature review on the prerequisite of HIV-1 PR action
leading to the release of the infectious virion is absent. Herein, recent advances (both computationally
and experimentally) on the recognition mode and reaction mechanism of HIV-1 PR
involving its natural targets are provided. This review features more than 80 articles from
reputable journals. Recognition of the natural Gag and Gag-Pol cleavage junctions by this
enzyme and its mutant analogs was first addressed. Thereafter, a comprehensive dissect of
the enzymatic mechanism of HIV-1 PR on its natural polypeptide sequences from literature
was put together. In addition, we highlighted ongoing research topics in which in silico
methods could be harnessed to provide deeper insights into the catalytic mechanism of the
HIV-1 protease in the presence of its natural substrates at the molecular level. Understanding
the recognition and catalytic mechanism of HIV-1 PR leading to the release of an infective
virion, which advertently affects the immune system, will assist in designing mechanismbased
inhibitors with improved bioactivity.
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Affiliation(s)
- Monsurat M. Lawal
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Zainab K. Sanusi
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Glenn E.M. Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Bahareh Honarparvar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Hendrik G. Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
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7
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Kumar M, Mandal K, Blakeley MP, Wymore T, Kent SBH, Louis JM, Das A, Kovalevsky A. Visualizing Tetrahedral Oxyanion Bound in HIV-1 Protease Using Neutrons: Implications for the Catalytic Mechanism and Drug Design. ACS OMEGA 2020; 5:11605-11617. [PMID: 32478251 PMCID: PMC7254801 DOI: 10.1021/acsomega.0c00835] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 04/30/2020] [Indexed: 06/11/2023]
Abstract
HIV-1 protease is indispensable for virus propagation and an important therapeutic target for antiviral inhibitors to treat AIDS. As such inhibitors are transition-state mimics, a detailed understanding of the enzyme mechanism is crucial for the development of better anti-HIV drugs. Here, we used room-temperature joint X-ray/neutron crystallography to directly visualize hydrogen atoms and map hydrogen bonding interactions in a protease complex with peptidomimetic inhibitor KVS-1 containing a reactive nonhydrolyzable ketomethylene isostere, which, upon reacting with the catalytic water molecule, is converted into a tetrahedral intermediate state, KVS-1TI. We unambiguously determined that the resulting tetrahedral intermediate is an oxyanion, rather than the gem-diol, and both catalytic aspartic acid residues are protonated. The oxyanion tetrahedral intermediate appears to be unstable, even though the negative charge on the oxyanion is delocalized through a strong n → π* hyperconjugative interaction into the nearby peptidic carbonyl group of the inhibitor. To better understand the influence of the ketomethylene isostere as a protease inhibitor, we have also examined the protease structure and binding affinity with keto-darunavir (keto-DRV), which similar to KVS-1 includes the ketomethylene isostere. We show that keto-DRV is a significantly less potent protease inhibitor than DRV. These findings shed light on the reaction mechanism of peptide hydrolysis catalyzed by HIV-1 protease and provide valuable insights into further improvements in the design of protease inhibitors.
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Affiliation(s)
- Mukesh Kumar
- Protein Crystallography
Section, Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - Kalyaneswar Mandal
- Departments of Chemistry, and Biochemistry and Molecular Biology,
Institute for Biophysical Dynamics, University
of Chicago, Chicago, Illinois 60637, United States
| | - Matthew P. Blakeley
- Large Scale Structures Group, Institut Laue−Langevin, 38000 Grenoble, France
| | - Troy Wymore
- Department of Chemistry, University
of Michigan, Ann Arbor, Michigan 48109, United States
| | - Stephen B. H. Kent
- Departments of Chemistry, and Biochemistry and Molecular Biology,
Institute for Biophysical Dynamics, University
of Chicago, Chicago, Illinois 60637, United States
| | - 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
| | - Amit Das
- Protein Crystallography
Section, Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - Andrey Kovalevsky
- Neutron Scattering
Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
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8
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Novel radial distribution function approach in the study of point mutations: the HIV-1 protease case study. Future Med Chem 2020; 12:1025-1036. [PMID: 32319305 DOI: 10.4155/fmc-2020-0042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background: Mutations are one of the engines of evolution. Under constant stress pressure, mutations can lead to the emergence of unwanted, drug-resistant entities. Methodology: The radial distribution function weighted by the number of valence shell electrons is used to design quantitative structure-activity relationship (QSAR) model relating descriptors with the inhibition constant for a series of wild-type HIV-1 protease inhibitor complexes. The residuals of complexes with mutant HIV-1 protease were correlated with the energy of the highest occupied molecular orbitals of the residues introduced to enzyme via point mutations. Conclusion: Successful identification of residues Ile3, Asp25, Val32 and Ile50 as the one whose substitution influences the inhibition constant the most, demonstrates the potential of the proposed methodology for the study of the effects of point mutations.
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9
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Novak J, Grishina MA, Potemkin VA. The Influence of Hydrogen Atoms on the Performance of Radial Distribution Function-Based Descriptors in the Chemoinformatic Studies of HIV-1 Protease Complexes with Inhibitors. Curr Drug Discov Technol 2020; 18:414-422. [PMID: 31899678 DOI: 10.2174/1570163817666200102130415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 11/08/2019] [Accepted: 11/25/2019] [Indexed: 11/22/2022]
Abstract
AIMS The aim of this letter is to explore the influence of adding hydrogen atoms to the crystallographic structures of HIV-1 protease complexes with a series of inhibitors on the performance of radial distribution function based descriptors recently introduced in chemoinformatic studies. BACKGROUND Quite recently the successful application of molecular descriptors based on a radial distribution function to correlate it with biologically interesting properties of a ligand - enzyme complex was demonstrated. Except its predictive power, the analysis of atoms with dominant contributions to the RDFs can be used to identify relevant atoms and interactions. Since original paper was published on dataset consisting of the X-ray structures of complexes without hydrogen atoms, we wonder weather addition of light atoms can provide us new piece of information. OBJECTIVE The primarily objective is to create the model correlating the RDF based descriptors and physicochemical properties of the HIV-1 protease complexes with inhibitors with hydrogen atoms. Then, we will compare the performance of new model with previous one, where the hydrogen atoms were discarded. Information about interactions between the enzyme and the inhibitors will be extracted from the analysis of the RDF. METHODS The radial distribution function descriptor weighted by the number of valence shell electrons has proven to be sensitive to the changes in the structure of the enzyme and enzyme-ligand complexes. For each structure in our data set, RDF will be calculated and using multiple linear regression method the mathematical model will be designed correlating RDF based descriptors and the physicochemical properties. Statistical analysis of the atom's contribution to the total RDF will reveal relevant interactions. RESULTS The applicability of RDF based descriptor for the correlation with pKi and EC50 values is demonstrated, while simple models containing only two or three parameters are able to explain 78 and 86 % of the variance, respectively. The models with explicitly included hydrogens are of comparable quality with the previous models without hydrogens. The analysis of the atom's dominant contributions highlighted the importance of the hydroxyl groups of the inhibitor near the Asp25 and Asp25' residues when it is bounded to the protease. CONCLUSION Models based on the RDF weighted by the number of valence shell electrons for correlating small number of molecular descriptors and physicocehmical properties for structures with and without hydrogens are of comparable quality and both can be used for identification of relevant functional groups and interactions. Other: Our approach can be integrated to the next generation virtual screening methods, because is fast, reliable with high predictability potential.
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Affiliation(s)
- Jurica Novak
- South Ural State University, 20-A, Tchaikovsky Str., Chelyabinsk 454080, Russian Federation
| | - Maria A Grishina
- South Ural State University, 20-A, Tchaikovsky Str., Chelyabinsk 454080, Russian Federation
| | - Vladimir A Potemkin
- South Ural State University, 20-A, Tchaikovsky Str., Chelyabinsk 454080, Russian Federation
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10
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Sanusi ZK, Lawal MM, Govender T, Maguire GEM, Honarparvar B, Kruger HG. Theoretical Model for HIV-1 PR That Accounts for Substrate Recognition and Preferential Cleavage of Natural Substrates. J Phys Chem B 2019; 123:6389-6400. [DOI: 10.1021/acs.jpcb.9b02207] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Zainab K. Sanusi
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Monsurat M. Lawal
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
| | | | - Glenn E. M. Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
- School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Bahareh Honarparvar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
| | - Hendrik G. Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa
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11
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Lawal MM, Sanusi ZK, Govender T, Tolufashe GF, Maguire GEM, Honarparvar B, Kruger HG. Unraveling the concerted catalytic mechanism of the human immunodeficiency virus type 1 (HIV-1) protease: a hybrid QM/MM study. Struct Chem 2018. [DOI: 10.1007/s11224-018-1251-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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12
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Thacker JCR, Vincent MA, Popelier PLA. Using the Relative Energy Gradient Method with Interacting Quantum Atoms to Determine the Reaction Mechanism and Catalytic Effects in the Peptide Hydrolysis in HIV-1 Protease. Chemistry 2018; 24:11200-11210. [PMID: 29802794 PMCID: PMC6099506 DOI: 10.1002/chem.201802035] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Indexed: 11/10/2022]
Abstract
The reaction mechanism in an active site is of the utmost importance when trying to understand the role that an enzyme plays in biological processes. In a recently published paper [Theor. Chem. Acc. 2017, 136, 86], we formalised the Relative Energy Gradient (REG) method for automating an Interacting Quantum Atoms (IQA) analysis. Here, the REG method is utilised to determine the mechanism of peptide hydrolysis in the aspartic active site of the enzyme HIV-1 Protease. Using the REG method along with the IQA approach we determine the mechanism of peptide hydrolysis without employing any arbitrary parameters and with remarkable ease (albeit at large computational cost: the system contains 133 atoms, which means that there are 17 689 individual IQA terms to be calculated). When REG and IQA work together it is possible to determine a reaction mechanism at atomistic resolution from data directly derived from quantum calculations, without arbitrary parameters. Moreover, the mechanism determined by this novel method gives concrete insight into how the active site residues catalyse peptide hydrolysis.
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Affiliation(s)
- Joseph C. R. Thacker
- Manchester Institute of Biotechnology (MIB)131 Princess StreetManchesterM1 7DNUK
- School of ChemistryUniversity of ManchesterOxford RoadManchesterM13 9PLUK
| | - Mark A. Vincent
- Manchester Institute of Biotechnology (MIB)131 Princess StreetManchesterM1 7DNUK
- School of ChemistryUniversity of ManchesterOxford RoadManchesterM13 9PLUK
| | - Paul L. A. Popelier
- Manchester Institute of Biotechnology (MIB)131 Princess StreetManchesterM1 7DNUK
- School of ChemistryUniversity of ManchesterOxford RoadManchesterM13 9PLUK
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13
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Calixto AR, Ramos MJ, Fernandes PA. Influence of Frozen Residues on the Exploration of the PES of Enzyme Reaction Mechanisms. J Chem Theory Comput 2017; 13:5486-5495. [DOI: 10.1021/acs.jctc.7b00768] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Ana R. Calixto
- UCIBIO, REQUIMTE,
Departamento de Química
e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - Maria J. Ramos
- UCIBIO, REQUIMTE,
Departamento de Química
e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
| | - Pedro A. Fernandes
- UCIBIO, REQUIMTE,
Departamento de Química
e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal
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14
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Krzemińska A, Moliner V, Świderek K. Dynamic and Electrostatic Effects on the Reaction Catalyzed by HIV-1 Protease. J Am Chem Soc 2016; 138:16283-16298. [PMID: 27935692 DOI: 10.1021/jacs.6b06856] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
HIV-1 Protease (HIV-1 PR) is one of the three enzymes essential for the replication process of HIV-1 virus, which explains why it has been the main target for design of drugs against acquired immunodeficiency syndrome (AIDS). This work is focused on exploring the proteolysis reaction catalyzed by HIV-1 PR, with special attention to the dynamic and electrostatic effects governing its catalytic power. Free energy surfaces for all possible mechanisms have been computed in terms of potentials of mean force (PMFs) within hybrid QM/MM potentials, with the QM subset of atoms described at semiempirical (AM1) and DFT (M06-2X) level. The results suggest that the most favorable reaction mechanism involves formation of a gem-diol intermediate, whose decomposition into the product complex would correspond to the rate-limiting step. The agreement between the activation free energy of this step with experimental data, as well as kinetic isotope effects (KIEs), supports this prediction. The role of the protein dynamic was studied by protein isotope labeling in the framework of the Variational Transition State Theory. The predicted enzyme KIEs, also very close to the values measured experimentally, reveal a measurable but small dynamic effect. Our calculations show how the contribution of dynamic effects to the effective activation free energy appears to be below 1 kcal·mol-1. On the contrary, the electric field created by the protein in the active site of the enzyme emerges as being critical for the electronic reorganization required during the reaction. These electrostatic properties of the active site could be used as a mold for future drug design.
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Affiliation(s)
- Agnieszka Krzemińska
- Institute of Applied Radiation Chemistry, Faculty of Chemistry, Lodz University of Technology , Zeromskiego 116, 90-924 Lodz, Poland
| | - Vicent Moliner
- Departament de Química Física i Analítica, Universitat Jaume I , 12071 Castelló, Spain
| | - Katarzyna Świderek
- Institute of Applied Radiation Chemistry, Faculty of Chemistry, Lodz University of Technology , Zeromskiego 116, 90-924 Lodz, Poland.,Departament de Química Física i Analítica, Universitat Jaume I , 12071 Castelló, Spain
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15
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Ribeiro AJM, Santos-Martins D, Russo N, Ramos MJ, Fernandes PA. Enzymatic Flexibility and Reaction Rate: A QM/MM Study of HIV-1 Protease. ACS Catal 2015. [DOI: 10.1021/acscatal.5b00759] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- António J. M. Ribeiro
- UCBIO,
REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
- Dipartimento
di Chimica, Università della Calabria, 87036 Arcavacata
di Rende, Italia
| | - Diogo Santos-Martins
- UCBIO,
REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
| | - Nino Russo
- Dipartimento
di Chimica, Università della Calabria, 87036 Arcavacata
di Rende, Italia
| | - Maria J. Ramos
- UCBIO,
REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
| | - Pedro A. Fernandes
- UCBIO,
REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
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16
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Gauthier PPG, Lamothe M, Mahé A, Molero G, Nogués S, Hodges M, Tcherkez G. Metabolic origin of δ15 N values in nitrogenous compounds from Brassica napus L. leaves. PLANT, CELL & ENVIRONMENT 2013; 36:128-37. [PMID: 22709428 DOI: 10.1111/j.1365-3040.2012.02561.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Nitrogen isotope composition (δ(15) N) in plant organic matter is currently used as a natural tracer of nitrogen acquisition efficiency. However, the δ(15) N value of whole leaf material does not properly reflect the way in which N is assimilated because isotope fractionations along metabolic reactions may cause substantial differences among leaf compounds. In other words, any change in metabolic composition or allocation pattern may cause undesirable variability in leaf δ(15) N. Here, we investigated the δ(15) N in different leaf fractions and individual metabolites from rapeseed (Brassica napus) leaves. We show that there were substantial differences in δ(15) N between nitrogenous compounds (up to 30‰) and the content in ((15) N enriched) nitrate had a clear influence on leaf δ(15) N. Using a simple steady-state model of day metabolism, we suggest that the δ(15) N value in major amino acids was mostly explained by isotope fractionation associated with isotope effects on enzyme-catalysed reactions in primary nitrogen metabolism. δ(15) N values were further influenced by light versus dark conditions and the probable occurrence of alternative biosynthetic pathways. We conclude that both biochemical pathways (that fractionate between isotopes) and nitrogen sources (used for amino acid production) should be considered when interpreting the δ(15) N value of leaf nitrogenous compounds.
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Affiliation(s)
- Paul P G Gauthier
- Institut de Biologie des Plantes, CNRS UMR 8618 Plateforme Métabolisme Métabolome, Université Paris Sud, Orsay Cedex, France.
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17
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Transition states of native and drug-resistant HIV-1 protease are the same. Proc Natl Acad Sci U S A 2012; 109:6543-8. [PMID: 22493227 DOI: 10.1073/pnas.1202808109] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
HIV-1 protease is an important target for the treatment of HIV/AIDS. However, drug resistance is a persistent problem and new inhibitors are needed. An approach toward understanding enzyme chemistry, the basis of drug resistance, and the design of powerful inhibitors is to establish the structure of enzymatic transition states. Enzymatic transition structures can be established by matching experimental kinetic isotope effects (KIEs) with theoretical predictions. However, the HIV-1 protease transition state has not been previously resolved using these methods. We have measured primary (14)C and (15)N KIEs and secondary (3)H and (18)O KIEs for native and multidrug-resistant HIV-1 protease (I84V). We observed (14)C KIEs ((14)V/K) of 1.029 ± 0.003 and 1.025 ± 0.005, (15)N KIEs ((15)V/K) of 0.987 ± 0.004 and 0.989 ± 0.003, (18)O KIEs ((18)V/K) of 0.999 ± 0.003 and 0.993 ± 0.003, and (3)H KIEs ((3)V/K) KIEs of 0.968 ± 0.001 and 0.976 ± 0.001 for the native and I84V enzyme, respectively. The chemical reaction involves nucleophilic water attack at the carbonyl carbon, proton transfer to the amide nitrogen leaving group, and C-N bond cleavage. A transition structure consistent with the KIE values involves proton transfer from the active site Asp-125 (1.32 Å) with partial hydrogen bond formation to the accepting nitrogen (1.20 Å) and partial bond loss from the carbonyl carbon to the amide leaving group (1.52 Å). The KIEs measured for the native and I84V enzyme indicate nearly identical transition states, implying that a true transition-state analogue should be effective against both enzymes.
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18
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Singh N, Frushicheva MP, Warshel A. Validating the vitality strategy for fighting drug resistance. Proteins 2012; 80:1110-22. [PMID: 22275047 DOI: 10.1002/prot.24012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Revised: 11/28/2011] [Accepted: 12/06/2011] [Indexed: 11/08/2022]
Abstract
The current challenge in designing effective drugs against HIV-1 is to find novel candidates with high potency, but with a lower susceptibility to mutations associated with drug resistance. Trying to address this challenge, we developed in our previous study (Ishikita and Warshel, Angew Chem Int Ed Engl 2008; 47:697-700) a novel computational strategy for fighting drug resistance by predicting the likely moves of the virus through constraints on binding and catalysis. This has been based on calculating the ratio between the vitality values ((K(i) k(cat)/K(M))(mutant)/(K(i) k(cat)/K(M))(wild-type)) and using it as a guide for predicting the moves of the virus. The corresponding calculations of the binding affinity, K(i), were carried out using the semi-macroscopic version of the protein dipole Langevin dipole (PDLD/S) in its linear response approximation (LRA) in its β version (PDLD/S-LRA/β). We also calculate the proteolytic efficiency, k(cat)/K(M), by evaluating the transition state (TS) binding free energies using the PDLD/S-LRA/β method. Here we provide an extensive validation of our strategy by calculating the vitality of six existing clinical and experimental drug candidates. It is found that the computationally determined vitalities correlate reasonably well with those derived from the corresponding experimental data. This indicates that the calculated vitality may be used to identify mutations that would be most effective for the survival of the virus. Thus, it should be possible to use our approach in screening for mutations that would provide the most effective resistance to any proposed antiviral drug. This ability should be very useful in guiding the design of drug molecules that will lead to the slowest resistance.
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Affiliation(s)
- Nidhi Singh
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-1062, USA
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19
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HORI TAKUMI, TAKAHASHI HIDEAKI, NITTA TOMOSHIGE. HYBRID QUANTUM MECHANICAL/MOLECULAR MECHANICAL APPROACH TO ENZYMATIC REACTIONS BY UTILIZING THE REAL-SPACE GRID TECHNIQUE. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2011. [DOI: 10.1142/s0219633605001799] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We have developed a novel quantum mechanical/molecular mechanical (QM/MM) code based on the real-space grids in order to realize high parallel efficiency. The details of the methodology and its parallel implementation have been presented. We have computed the electronic state of the QM subsystem using the Kohn–Sham density functional theory, where the one-electron wave functions have been expressed by the real-space grids distributed over a cubic cell. We have performed QM/MM simulations for the peptide hydrolysis in human immunodeficiency virus type-1 aspartyl protease in order to examine the reliability of the present QM/MM approach. The activation energy obtained by the present calculations shows a good agreement with the experimental results and that of the other QM/MM method. Finally, we have parallelized the whole code and found that the grid approach can afford high parallel efficiency (~80%) in such a large scale electronic structure calculation. We conclude that the QM/MM approach utilizing real-space grids is adequate and efficient for the study of the enzymatic reactions.
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Affiliation(s)
- TAKUMI HORI
- Division of Chemical Engineering, Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, Machikaneyama-cho 1-3, Toyonaka, Osaka 560-8531, Japan
| | - HIDEAKI TAKAHASHI
- Division of Chemical Engineering, Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, Machikaneyama-cho 1-3, Toyonaka, Osaka 560-8531, Japan
| | - TOMOSHIGE NITTA
- Division of Chemical Engineering, Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, Machikaneyama-cho 1-3, Toyonaka, Osaka 560-8531, Japan
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20
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Computational insights into the development of novel therapeutic strategies for Alzheimer's disease. Future Med Chem 2011; 1:119-35. [PMID: 21426072 DOI: 10.4155/fmc.09.10] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND β-amyloidosis and oxidative stress have been implicated as root causes of Alzheimer's disease (AD). Current potential therapeutic strategies for the treatment of AD include inhibition of amyloid β (Aβ) production, stimulation of Aβ degradation and prevention of Aβ oligomerization. However, efforts in this direction are hindered by the lack of understanding of the biochemical processes occurring at the atomic level in AD. DISCUSSION A radically different approach to achieve this goal would be the application of comprehensive theoretical and computational techniques such as molecular dynamics, quantum mechanics, hybrid quantum mechanics/molecular mechanics, bioinformatics and rotational spectroscopy to investigate complex chemical and physical processes in β-amyloidosis and the oxidative stress mechanism. CONCLUSION Results obtained from these studies will provide an atomic level understanding of biochemical processes occurring in AD and advance efforts to develop effective therapeutic strategies for this disease.
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21
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Garrec J, Sautet P, Fleurat-Lessard P. Understanding the HIV-1 Protease Reactivity with DFT: What Do We Gain from Recent Functionals? J Phys Chem B 2011; 115:8545-58. [DOI: 10.1021/jp200565w] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- J. Garrec
- Université de Lyon,CNRS, École Normale Supérieure de Lyon, Laboratoire de Chimie, 46 alléed’Italie, F-69364 Lyon Cedex 07
| | - P. Sautet
- Université de Lyon,CNRS, École Normale Supérieure de Lyon, Laboratoire de Chimie, 46 alléed’Italie, F-69364 Lyon Cedex 07
| | - P. Fleurat-Lessard
- Université de Lyon,CNRS, École Normale Supérieure de Lyon, Laboratoire de Chimie, 46 alléed’Italie, F-69364 Lyon Cedex 07
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22
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Bora RP, Barman A, Zhu X, Ozbil M, Prabhakar R. Which One Among Aspartyl Protease, Metallopeptidase, and Artificial Metallopeptidase is the Most Efficient Catalyst in Peptide Hydrolysis? J Phys Chem B 2010; 114:10860-75. [DOI: 10.1021/jp104294x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Ram Prasad Bora
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146
| | - Arghya Barman
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146
| | - Xiaoxia Zhu
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146
| | - Mehmet Ozbil
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146
| | - Rajeev Prabhakar
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146
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23
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Tcherkez G. Natural 15N/ 14N isotope composition in C 3 leaves: are enzymatic isotope effects informative for predicting the 15N-abundance in key metabolites? FUNCTIONAL PLANT BIOLOGY : FPB 2010; 38:1-12. [PMID: 32480857 DOI: 10.1071/fp10091] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Accepted: 10/24/2010] [Indexed: 06/11/2023]
Abstract
Although nitrogen isotopes are viewed as important tools for understanding plant N acquisition and allocation, the current interpretation of natural 15N-abundances (δ15N values) is often impaired by substantial variability among individuals or between species. Such variability is likely to stem from the fact that 15N-abundance of assimilated N is not preserved during N metabolism and redistribution within the plant; that is, 14N/15N isotope effects associated with N metabolic reactions are certainly responsible for isotopic shifts between organic-N (amino acids) and absorbed inorganic N (nitrate). Therefore, to gain insights into the metabolic origin of 15N-abundance in plants, the present paper reviews enzymatic isotope effects and integrates them into a metabolic model at the leaf level. Using simple steady-state equations which satisfactorily predict the δ15N value of amino acids, it is shown that the sensitivity of δ15N values to both photorespiratory and N-input (reduction by nitrate reductase) rates is quite high. In other words, the variability in δ15N values observed in nature might originate from subtle changes in metabolic fluxes or environment-driven effects, such as stomatal closure that in turn changes v0, the Rubisco-catalysed oxygenation rate.
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Affiliation(s)
- Guillaume Tcherkez
- Institut de Biologie des Plantes, CNRS UMR 8618, Université Paris-Sud 11, 91405 Orsay Cedex, France. Email
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24
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Bihani S, Das A, Prashar V, Ferrer JL, Hosur MV. X-ray structure of HIV-1 protease in situ product complex. Proteins 2009; 74:594-602. [DOI: 10.1002/prot.22174] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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25
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Singh R, Barman A, Prabhakar R. Computational Insights into Aspartyl Protease Activity of Presenilin 1 (PS1) Generating Alzheimer Amyloid β-Peptides (Aβ40 and Aβ42). J Phys Chem B 2009; 113:2990-9. [DOI: 10.1021/jp811154w] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Rajiv Singh
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146
| | - Arghya Barman
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146
| | - Rajeev Prabhakar
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146
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26
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Sayer JM, Liu F, Ishima R, Weber IT, Louis JM. Effect of the active site D25N mutation on the structure, stability, and ligand binding of the mature HIV-1 protease. J Biol Chem 2008; 283:13459-70. [PMID: 18281688 DOI: 10.1074/jbc.m708506200] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
All aspartic proteases, including retroviral proteases, share the triplet DTG critical for the active site geometry and catalytic function. These residues interact closely in the active, dimeric structure of HIV-1 protease (PR). We have systematically assessed the effect of the D25N mutation on the structure and stability of the mature PR monomer and dimer. The D25N mutation (PR(D25N)) increases the equilibrium dimer dissociation constant by a factor >100-fold (1.3 +/- 0.09 microm) relative to PR. In the absence of inhibitor, NMR studies reveal clear structural differences between PR and PR(D25N) in the relatively mobile P1 loop (residues 79-83) and flap regions, and differential scanning calorimetric analyses show that the mutation lowers the stabilities of both the monomer and dimer folds by 5 and 7.3 degrees C, respectively. Only minimal differences are observed in high resolution crystal structures of PR(D25N) complexed to darunavir (DRV), a potent clinical inhibitor, or a non-hydrolyzable substrate analogue, Ac-Thr-Ile-Nle-r-Nle-Gln-Arg-NH(2) (RPB), as compared with PR.DRV and PR.RPB complexes. Although complexation with RPB stabilizes both dimers, the effect on their T(m) is smaller for PR(D25N) (6.2 degrees C) than for PR (8.7 degrees C). The T(m) of PR(D25N).DRV increases by only 3 degrees C relative to free PR(D25N), as compared with a 22 degrees C increase for PR.DRV, and the mutation increases the ligand dissociation constant of PR(D25N).DRV by a factor of approximately 10(6) relative to PR.DRV. These results suggest that interactions mediated by the catalytic Asp residues make a major contribution to the tight binding of DRV to PR.
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Affiliation(s)
- Jane M Sayer
- Laboratory of Chemical Physics, NIDDK, National Institutes of Health, Bethesda, Maryland 20892-0520, USA
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27
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Altoè P, Stenta M, Bottoni A, Garavelli M. A tunable QM/MM approach to chemical reactivity, structure and physico-chemical properties prediction. Theor Chem Acc 2007. [DOI: 10.1007/s00214-007-0275-9] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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28
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Das A, Prashar V, Mahale S, Serre L, Ferrer JL, Hosur MV. Crystal structure of HIV-1 protease in situ product complex and observation of a low-barrier hydrogen bond between catalytic aspartates. Proc Natl Acad Sci U S A 2006; 103:18464-9. [PMID: 17116869 PMCID: PMC1693685 DOI: 10.1073/pnas.0605809103] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2006] [Indexed: 11/18/2022] Open
Abstract
HIV-1 protease is an effective target for designing drugs against AIDS, and structural information about the true transition state and the correct mechanism can provide important inputs. We present here the three-dimensional structure of a bi-product complex between HIV-1 protease and the two cleavage product peptides AETF and YVDGAA. The structure, refined against synchrotron data to 1.65 A resolution, shows the occurrence of the cleavage reaction in the crystal, with the product peptides still held in the enzyme active site. The separation between the scissile carbon and nitrogen atoms is 2.67 A, which is shorter than a normal van der Waal separation, but it is much longer than a peptide bond length. The substrate is thus in a stage just past the G'Z intermediate described in Northrop's mechanism [Northrop DB (2001) Acc Chem Res 34:790-797]. Because the products are generated in situ, the structure, by extrapolation, can give insight into the mechanism of the cleavage reaction. Both oxygens of the generated carboxyl group form hydrogen bonds with atoms at the catalytic center: one to the OD2 atom of a catalytic aspartate and the other to the scissile nitrogen atom. The latter hydrogen bond may have mediated protonation of scissile nitrogen, triggering peptide bond cleavage. The inner oxygen atoms of the catalytic aspartates in the complex are 2.30 A apart, indicating a low-barrier hydrogen bond between them at this stage of the reaction, an observation not included in Northrop's proposal. This structure forms a template for designing mechanism-based inhibitors.
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Affiliation(s)
- Amit Das
- Protein Crystallography Section, Solid State Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - Vishal Prashar
- Protein Crystallography Section, Solid State Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - Smita Mahale
- National Institute for Research in Reproductive Health, Parel, Mumbai 400012, India; and
| | - L. Serre
- Institute de Biologie Structurale Jean-Pierre Ebel, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Joseph Fourier, 38027 Grenoble Cedex 1, France
| | - J.-L. Ferrer
- Institute de Biologie Structurale Jean-Pierre Ebel, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Université Joseph Fourier, 38027 Grenoble Cedex 1, France
| | - M. V. Hosur
- Protein Crystallography Section, Solid State Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
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29
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Jiang L, Liu Z, Liang Z, Gao Y. An artificial aspartic proteinase system. Bioorg Med Chem 2005; 13:3673-80. [PMID: 15862996 DOI: 10.1016/j.bmc.2005.03.026] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2005] [Revised: 03/15/2005] [Accepted: 03/15/2005] [Indexed: 11/26/2022]
Abstract
A series of aza crown ether derivatives with or without carboxyl groups in their side arms were synthesized and the former showed deacylation activities toward amino acid p-nitrophenyl ester hydrohalides. Substrate-selective phenomena were also observed. The relationship between the structures and deacylation activities of corresponding compounds suggested a nucleophilic catalytic mechanism. The results partially simulate some aspartic proteinases in the case of catalytic mechanism and are also useful for us to understand the detailed catalytic process of aspartic proteinases.
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Affiliation(s)
- Lin Jiang
- Technical Institute of Physics and Chemistry, Chinese Academy of Sciences (CAS), Box 5131, Beijing 100101, PR China
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30
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Adler M, Adler S, Boche G. Tetrahedral intermediates in reactions of carboxylic acid derivatives with nucleophiles. J PHYS ORG CHEM 2005. [DOI: 10.1002/poc.807] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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31
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Kovalskyy D, Dubyna V, Mark AE, Kornelyuk A. A molecular dynamics study of the structural stability of HIV-1 protease under physiological conditions: The role of Na+ ions in stabilizing the active site. Proteins 2004; 58:450-8. [DOI: 10.1002/prot.20304] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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32
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Trylska J, Grochowski P, McCammon JA. The role of hydrogen bonding in the enzymatic reaction catalyzed by HIV-1 protease. Protein Sci 2004; 13:513-28. [PMID: 14739332 PMCID: PMC2286701 DOI: 10.1110/ps.03372304] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The hydrogen-bond network in various stages of the enzymatic reaction catalyzed by HIV-1 protease was studied through quantum-classical molecular dynamics simulations. The approximate valence bond method was applied to the active site atoms participating directly in the rearrangement of chemical bonds. The rest of the protein with explicit solvent was treated with a classical molecular mechanics model. Two possible mechanisms were studied, general-acid/general-base (GA/GB) with Asp 25 protonated at the inner oxygen, and a direct nucleophilic attack by Asp 25. Strong hydrogen bonds leading to spontaneous proton transfers were observed in both reaction paths. A single-well hydrogen bond was formed between the peptide nitrogen and outer oxygen of Asp 125. The proton was diffusely distributed with an average central position and transferred back and forth on a picosecond scale. In both mechanisms, this interaction helped change the peptide-bond hybridization, increased the partial charge on peptidyl carbon, and in the GA/GB mechanism, helped deprotonate the water molecule. The inner oxygens of the aspartic dyad formed a low-barrier, but asymmetric hydrogen bond; the proton was not positioned midway and made a slightly elongated covalent bond, transferring from one to the other aspartate. In the GA/GB mechanism both aspartates may help deprotonate the water molecule. We observed the breakage of the peptide bond and found that the protonation of the peptidyl amine group was essential for the peptide-bond cleavage. In studies of the direct nucleophilic mechanism, the peptide carbon of the substrate and oxygen of Asp 25 approached as close as 2.3 A.
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Affiliation(s)
- Joanna Trylska
- Department of Chemistry and Biochemistry, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
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33
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34
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Trylska J, Bała P, Geller M, Grochowski P. Molecular dynamics simulations of the first steps of the reaction catalyzed by HIV-1 protease. Biophys J 2002; 83:794-807. [PMID: 12124265 PMCID: PMC1302187 DOI: 10.1016/s0006-3495(02)75209-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The mechanism of the first steps of the reaction catalyzed by HIV-1 protease was studied through molecular dynamics simulations. The potential energy surface in the active site was generated using the approximate valence bond method. The approximate valence bond (AVB) method was parameterized based on density functional calculations. The surrounding protein and explicit water environment was modeled with conventional, classical force field. The calculations were performed based on HIV-1 protease complexed with the MVT-101 inhibitor that was modified to a model substrate. The protonation state of the catalytic aspartates was determined theoretically. Possible reaction mechanisms involving the lytic water molecule are accounted for in this study. The modeled steps include the dissociation of the lytic water molecule and proton transfer onto Asp-125, the nucleophilic attack followed by a proton transfer onto peptide nitrogen. The simulations show that in the active site most preferable energetically are structures consisting of ionized or polarized molecular fragments that are not accounted for in conventional molecular dynamics. The mobility of the lytic water molecule, the dynamics of the hydrogen bond network, and the conformation of the aspartates in the active center were analyzed.
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Affiliation(s)
- Joanna Trylska
- Interdisciplinary Centre for Mathematical and Computational Modelling, Warsaw University, 02-106 Warsaw, Poland.
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35
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Okimoto N, Kitayama K, Hata M, Hoshino T, Tsuda M. Molecular dynamics simulations of a complex of HIV-1 protease and substrate: substrate-dependent efficiency of catalytic activity. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s0166-1280(00)00834-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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36
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Metzler DE, Metzler CM, Sauke DJ. Transferring Groups by Displacement Reactions. Biochemistry 2001. [DOI: 10.1016/b978-012492543-4/50015-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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37
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Alber F, Carloni P. Ab initio molecular dynamics studies on HIV-1 reverse transcriptase triphosphate binding site: implications for nucleoside-analog drug resistance. Protein Sci 2000; 9:2535-46. [PMID: 11206075 PMCID: PMC2144522 DOI: 10.1110/ps.9.12.2535] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Quantum-chemical methods are used to shed light on the functional role of residues involved in the resistance of HIV-1 reverse transcriptase against nucleoside-analog drugs. Ab initio molecular dynamics simulations are carried out for models representing the adduct between the triphosphate substrate and the nucleoside binding site. The triphosphate is considered either deprotonated or protonated at the gamma-position. Although the protonated form already experiences large rearrangements in the ps time scale, the fully deprotonated state exhibits a previously unrecognized low-barrier hydrogen bond between Lys65 and gamma-phosphate. Absence of this interaction in Lys65-->Arg HIV-1 RT might play a prominent role in the resistance of this mutant for nucleoside analogs (Gu Z et al., 1994b, Antimicrob Agents Chemother 38:275-281; Zhang D et al., 1994, Antimicrob Agents Chemother 38:282-287). Water molecules present in the active site, not detected in the X-ray structure, form a complex H-bond network. Among these waters, one may be crucial for substrate recognition as it bridges Gln151 and Arg72 with the beta-phosphate. Absence of this stabilizing interaction in Gln151-->Met HIV-1 RT mutant may be a key factor for the known drug resistance of this mutant toward dideoxy-type drugs and AZT (Shirasaka T et al., 1995, Proc Natl Acad Sci USA 92:2398-2402: Iversen AK et al., 1996, J Virol 70:1086-1090).
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Affiliation(s)
- F Alber
- International School for Advanced Studies (SISSA) and Istituto Nazionale di Fisica della Materia, Trieste, Italy
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38
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Park H, Suh J, Lee S. Ab Initio Studies on the Catalytic Mechanism of Aspartic Proteinases: Nucleophilic versus General Acid/General Base Mechanism. J Am Chem Soc 2000. [DOI: 10.1021/ja992849p] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hwangseo Park
- Contribution from the Department of Chemistry and Center for Molecular Catalysis, Seoul National University, Seoul 151-742, South Korea
| | - Junghun Suh
- Contribution from the Department of Chemistry and Center for Molecular Catalysis, Seoul National University, Seoul 151-742, South Korea
| | - Sangyoub Lee
- Contribution from the Department of Chemistry and Center for Molecular Catalysis, Seoul National University, Seoul 151-742, South Korea
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39
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Tantillo DJ, Chen J, Houk KN. Theozymes and compuzymes: theoretical models for biological catalysis. Curr Opin Chem Biol 1998; 2:743-50. [PMID: 9914196 DOI: 10.1016/s1367-5931(98)80112-9] [Citation(s) in RCA: 192] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A theozyme is a theoretical enzyme constructed by computing the optimal geometry for transition-state stabilization by functional groups. It is created in order to permit quantitative assessment of catalytic function. Theozymes have been used to elucidate the role of transition-state stabilization in the mechanisms underlying enzyme- and antibody-catalyzed hydroxyepoxide cyclizations, eliminations and decarboxylations, peptide and ester hydrolyses, and pericyclic and radical reactions. The enzymes studied include orotodine monophosphate decarboxylase, HIV protease and ribonucleotide reductase.
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Affiliation(s)
- D J Tantillo
- Department of Chemistry and Biochemistry University of California 405 Hilgard Avenue Los Angeles CA 90095-1569 USA
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40
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Suh J, Hah SS. Organic Artificial Proteinase with Active Site Comprising Three Salicylate Residues. J Am Chem Soc 1998. [DOI: 10.1021/ja981379g] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Junghun Suh
- Contribution from the Department of Chemistry and Center for Molecular Catalysis, Seoul National University, Seoul 151-742, Korea
| | - Sang Soo Hah
- Contribution from the Department of Chemistry and Center for Molecular Catalysis, Seoul National University, Seoul 151-742, Korea
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41
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Venturini A, López-Ortiz F, Alvarez JM, González J. Theoretical Proposal of a Catalytic Mechanism for the HIV-1 Protease Involving an Enzyme-Bound Tetrahedral Intermediate. J Am Chem Soc 1998. [DOI: 10.1021/ja9728435] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Alessandro Venturini
- CNR-Istituto dei Composti del Carbonio contenenti Eteroatomi e loro Applicazioni, Via Gobetti 101 40064 Bologna, Italy Departamento de Geometría, Topología, y Química Orgánica Facultad de Ciencias Experimentales, Universidad de Almería Cañada San Urbano, s/n 04120 Almería, Spain Departamento de Química Orgánica e Inorgánica Universidad de Oviedo, 33071 Oviedo, Spain
| | - Fernando López-Ortiz
- CNR-Istituto dei Composti del Carbonio contenenti Eteroatomi e loro Applicazioni, Via Gobetti 101 40064 Bologna, Italy Departamento de Geometría, Topología, y Química Orgánica Facultad de Ciencias Experimentales, Universidad de Almería Cañada San Urbano, s/n 04120 Almería, Spain Departamento de Química Orgánica e Inorgánica Universidad de Oviedo, 33071 Oviedo, Spain
| | - Julia M. Alvarez
- CNR-Istituto dei Composti del Carbonio contenenti Eteroatomi e loro Applicazioni, Via Gobetti 101 40064 Bologna, Italy Departamento de Geometría, Topología, y Química Orgánica Facultad de Ciencias Experimentales, Universidad de Almería Cañada San Urbano, s/n 04120 Almería, Spain Departamento de Química Orgánica e Inorgánica Universidad de Oviedo, 33071 Oviedo, Spain
| | - Javier González
- CNR-Istituto dei Composti del Carbonio contenenti Eteroatomi e loro Applicazioni, Via Gobetti 101 40064 Bologna, Italy Departamento de Geometría, Topología, y Química Orgánica Facultad de Ciencias Experimentales, Universidad de Almería Cañada San Urbano, s/n 04120 Almería, Spain Departamento de Química Orgánica e Inorgánica Universidad de Oviedo, 33071 Oviedo, Spain
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42
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Qasmi D, de Rosny E, René L, Badet B, Vergely I, Boggetto N, Reboud-Ravaux M. Synthesis of N-glyoxylyl peptides and their in vitro evaluation as HIV-1 protease inhibitors. Bioorg Med Chem 1997; 5:707-14. [PMID: 9158869 DOI: 10.1016/s0968-0896(97)00016-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A series of novel synthetic peptides containing an N-terminal glyoxylyl function (CHOCO-) have been tested as inhibitors of HIV-1 protease. The N-glyoxylyl peptide CHOCO-Pro-Ile-Val-NH2, which fulfills the specificity requirements of the MA/CA protease cleavage site together with the criteria of transition state analogue of the catalyzed reaction, was found to be a moderate competitive inhibitor although favorable interactions were visualized between its hydrated form and the catalytic aspartates using molecular modeling. Increasing the length of the peptide sequence led to compounds acting only as substrates.
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Affiliation(s)
- D Qasmi
- Institut de Chimie des Substances Naturelles-CNRS, Gif-sur-Yvette, France
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43
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Silva AM, Cachau RE, Sham HL, Erickson JW. Inhibition and catalytic mechanism of HIV-1 aspartic protease. J Mol Biol 1996; 255:321-46. [PMID: 8551523 DOI: 10.1006/jmbi.1996.0026] [Citation(s) in RCA: 141] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The structure of the HIV-1 protease in complex with a pseudo-C2 symmetric inhibitor, which contains a central difluoroketone motif, has been determined with X-ray diffraction data extending to 1.7 A resolution. The electron density map clearly indicates that the inhibitor is bound in a symmetric fashion as the hydrated, or gemdiol, form of the difluoroketone. Refinement of the complex reveals a unique, and almost symmetric, set of interactions between the geminal hydroxyl groups, the geminal fluorine atoms, and the active-site aspartate residues. Several hydrogen bonding patterns are consistent with that conformation. The lowest energy hydrogen disposition, as determined by semiempirical energy calculations, shows only one active site aspartate protonated. A comparison between the corresponding dihedral angles of the difluorodiol core and those of a hydrated peptide bond analog, calculated ab-initio, shows that the inhibitor core is a mimic of a hydrated peptide bond in a gauche conformation. The feasibility of an anti-gauche transition for a peptide bond after hydration is verified by extensive molecular dynamics simulations. The simulations suggest that rotation about the C-N scissile bond would readily occur after hydration and would be driven by the optimization of the interactions of peptide side-chains with the enzyme. These results, together with the characterization of a transition state leading to bond breakage via a concerted exchange of two protons, suggest a proteolysis mechanism whereby only one active site aspartate is initially protonated. The steps of this mechanism are: asymmetric binding of the substrate; hydration of the peptidic carbonyl by an active site water; proton translocation between the active site aspartate residues simultaneously with carbonyl hydration; optimization of the binding of the entire substrate facilitated by the flexible structure of the hydrated peptide bond, which, in turn, forces the hydrated peptide bond to assume a gauche conformation; simultaneous proton exchange whereby one hydroxyl donates a proton to the charged aspartate, and, at the same time, the nitrogen lone pair accepts a proton from the other aspartate; and, bond breakage and regeneration of the initial protonation state of the aspartate residues.
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Affiliation(s)
- A M Silva
- Structural Biochemistry Program, National Cancer Institute, Frederick, MD 21702, USA
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44
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Meek TD, Rodriguez EJ, Angeles TS. Use of steady state kinetic methods to elucidate the kinetic and chemical mechanisms of retroviral proteases. Methods Enzymol 1994; 241:127-56. [PMID: 7854175 DOI: 10.1016/0076-6879(94)41063-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Despite the current plethora of structural data of HIV-1 protease and the availability of potent inhibitors, whose structures are based in part on the presumed mechanism of action of this enzyme, our actual understanding of its chemical mechanism has been until now based largely on the precedents of the mammalian and fungal aspartic proteases and static three-dimensional data. The available steady state kinetic data of the protease, as reviewed here, constitute a first step in a detailed description of the mechanism of the enzyme to complement the structural data.
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Affiliation(s)
- T D Meek
- Department of Cardiovascular Biochemistry, Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, New Jersey 08540
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