1
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Ntombela T, Seupersad A, Maseko S, Ibeji CU, Tolufashe G, Maphumulo SI, Naicker T, Baijnath S, Maguire GEM, Govender T, Lamichhane G, Honarparvar B, Kruger HG. Mechanistic insight on the inhibition of D, D-carboxypeptidase from Mycobacterium tuberculosis by β-lactam antibiotics: an ONIOM acylation study. J Biomol Struct Dyn 2021; 40:7645-7655. [PMID: 33719919 DOI: 10.1080/07391102.2021.1899052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Mycobacterium tuberculosis cell wall is intricate and impermeable to many agents. A D, D-carboxypeptidase (DacB1) is one of the enzymes involved in the biosynthesis of cell wall peptidoglycan and catalyzes the terminal D-alanine cleavage from pentapeptide precursors. Catalytic activity and mechanism by which DacB1 functions is poorly understood. Herein, we investigated the acylation mechanism of DacB1 by β-lactams using a 6-membered ring transition state model that involves a catalytic water molecule in the reaction pathway. The full transition states (TS) optimization plus frequency were achieved using the ONIOM (B3LYP/6-31 + G(d): AMBER) method. Subsequently, the activation free energies were computed via single-point calculations on fully optimized structures using B3LYP/6-311++(d,p): AMBER and M06-2X/6-311++(d,p): AMBER with an electronic embedding scheme. The 6-membered ring transition state is an effective model to examine the inactivation of DacB1 via acylation by β-lactams antibiotics (imipenem, meropenem, and faropenem) in the presence of the catalytic water. The ΔG# values obtained suggest that the nucleophilic attack on the carbonyl carbon is the rate-limiting step with 13.62, 19.60 and 30.29 kcal mol-1 for Imi-DacB1, Mero-DacB1 and Faro-DacB1, respectively. The electrostatic potential (ESP) and natural bond orbital (NBO) analysis provided significant electronic details of the electron-rich region and charge delocalization, respectively, based on the concerted 6-membered ring transition state. The stabilization energies of charge transfer within the catalytic reaction pathway concurred with the obtained activation free energies. The outcomes of this study provide important molecular insight into the inactivation of D, D-carboxypeptidase by β-lactams.
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Affiliation(s)
- Thandokuhle Ntombela
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Anya Seupersad
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Sibusiso Maseko
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Collins U Ibeji
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Gideon Tolufashe
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Siyabonga Innocent Maphumulo
- 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
| | - Sooraj Baijnath
- 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
| | - Thavendran Govender
- Faculty of Science and Agriculture, Department of Chemistry, University of Zululand, Richards Bay, South Africa
| | - Gyanu Lamichhane
- Center for Tuberculosis Research, Division of Infectious Diseases, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Bahareh Honarparvar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
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2
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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3
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Tolufashe GF, Sabe VT, Ibeji CU, Ntombela T, Govender T, Maguire GEM, Kruger HG, Lamichhane G, Honarparvar B. Structure and Function of L,D- and D,D-Transpeptidase Family Enzymes from Mycobacterium tuberculosis. Curr Med Chem 2020; 27:3250-3267. [PMID: 30501595 DOI: 10.2174/0929867326666181203150231] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 09/28/2018] [Accepted: 11/22/2018] [Indexed: 01/21/2023]
Abstract
Peptidoglycan, the exoskeleton of bacterial cell and an essential barrier that protects the cell, is synthesized by a pathway where the final steps are catalysed by transpeptidases. Knowledge of the structure and function of these vital enzymes that generate this macromolecule in M. tuberculosis could facilitate the development of potent lead compounds against tuberculosis. This review summarizes the experimental and computational studies to date on these aspects of transpeptidases in M. tuberculosis that have been identified and validated. The reported structures of L,D- and D,D-transpeptidases, as well as their functionalities, are reviewed and the proposed enzymatic mechanisms for L,D-transpeptidases are summarized. In addition, we provide bioactivities of known tuberculosis drugs against these enzymes based on both experimental and computational approaches. Advancing knowledge about these prominent targets supports the development of new drugs with novel inhibition mechanisms overcoming the current need for new drugs against tuberculosis.
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Affiliation(s)
- Gideon F Tolufashe
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Victor T Sabe
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Colins U Ibeji
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Thandokuhle Ntombela
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Glenn E M Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4001, South Africa.,School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Gyanu Lamichhane
- Division of Infectious Diseases, School of Medicine, Johns Hopkins University, Baltimore, MD 21287, United States
| | - Bahareh Honarparvar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4001, South Africa
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Sanusi ZK, Lawal MM, Govender T, Baijnath S, Naicker T, Maguire GEM, Honarparvar B, Kruger HG. Concerted hydrolysis mechanism of HIV-1 natural substrate against subtypes B and C-SA PR: insight through molecular dynamics and hybrid QM/MM studies. Phys Chem Chem Phys 2020; 22:2530-2539. [PMID: 31942584 DOI: 10.1039/c9cp05639d] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
It is well known that understanding the catalytic mechanism of HIV-1 PR is the rationale on which its inhibitors were developed; therefore, a better understanding of the mechanism of natural substrate hydrolysis is important. Herein, the reaction mechanism of HIV-1 natural substrates with subtypes B and common mutant in South Africa (subtype C-SA) protease were studied through transition state modelling, using a general acid-general base (GA-GB) one-step concerted process. The activation free energies of enzyme-substrate complexes were compared based on their rate of hydrolysis using a two-layered ONIOM (B3LYP/6-31++G(d,p):AMBER) method. We expanded our computational model to obtain a better understanding of the mechanism of hydrolysis as well as how the enzyme recognises or chooses the cleavage site of the scissile bonds. Using this model, a potential substrate-based inhibitor could be developed with better potency. The calculated activation energies of natural substrates in our previous study correlated well with experimental data. A similar trend was observed for the Gag and Gag-Pol natural substrates in the present work for both enzyme complexes except for the PR-RT substrate. Natural bond orbital (NBO) analysis was also applied to determine the extent of charge transfer within the QM part of both enzymes considered and the PR-RT natural substrate. The result of this study shows that the method can be utilized as a dependable computational technique to rationalize lead compounds against specific targets.
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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.
| | | | - Sooraj Baijnath
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4041, South Africa.
| | - Tricia Naicker
- 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. and 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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Farrokhzadeh A, Akher FB, Honarparvar B, Van Heerden FR. Modulation of the induced π-stacking interactions between the active site cytosine moiety of HIV-integrase and inhibitors containing substituted-methylbenzene: Physical nature of the positional and substituent effects. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2019.126950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Sabe VT, Tolufashe GF, Ibeji CU, Maseko SB, Govender T, Maguire GEM, Lamichhane G, Honarparvar B, Kruger HG. Identification of potent L,D-transpeptidase 5 inhibitors for Mycobacterium tuberculosis as potential anti-TB leads: virtual screening and molecular dynamics simulations. J Mol Model 2019; 25:328. [PMID: 31656981 DOI: 10.1007/s00894-019-4196-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 08/28/2019] [Indexed: 11/26/2022]
Abstract
Virtual screening is a useful in silico approach to identify potential leads against various targets. It is known that carbapenems (doripenem and faropenem) do not show any reasonable inhibitory activities against L,D-transpeptidase 5 (LdtMt5) and also an adduct of meropenem exhibited slow acylation. Since these drugs are active against L,D-transpeptidase 2 (LdtMt2), understanding the differences between these two enzymes is essential. In this study, a ligand-based virtual screening of 12,766 compounds followed by molecular dynamics (MD) simulations was applied to identify potential leads against LdtMt5. To further validate the obtained virtual screening ranking for LdtMt5, we screened the same libraries of compounds against LdtMt2 which had more experimetal and calculated binding energies reported. The observed consistency between the binding affinities of LdtMt2 validates the obtained virtual screening binding scores for LdtMt5. We subjected 37 compounds with docking scores ranging from - 7.2 to - 9.9 kcal mol-1 obtained from virtual screening for further MD analysis. A set of compounds (n = 12) from four antibiotic classes with ≤ - 30 kcal mol-1 molecular mechanics/generalized born surface area (MM-GBSA) binding free energies (ΔGbind) was characterized. A final set of that, all β-lactams (n = 4), was considered. The outcome of this study provides insight into the design of potential novel leads for LdtMt5. Graphical abstract.
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Affiliation(s)
- Victor T Sabe
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Gideon F Tolufashe
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Collins U Ibeji
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Sibusiso B Maseko
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Glenn E M Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
- School of Chemistry and Physics, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Gyanu Lamichhane
- Center for Tuberculosis Research, Division of Infectious Diseases, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Bahareh Honarparvar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa.
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Ibeji CU, Lawal MM, Tolufashe GF, Govender T, Naicker T, Maguire GEM, Lamichhane G, Kruger HG, Honarparvar B. The Driving Force for the Acylation of β-Lactam Antibiotics by L,D-Transpeptidase 2: Quantum Mechanics/Molecular Mechanics (QM/MM) Study. Chemphyschem 2019; 20:1126-1134. [PMID: 30969480 DOI: 10.1002/cphc.201900173] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 03/13/2019] [Indexed: 11/06/2022]
Abstract
β-lactam antibiotics, which are used to treat infectious diseases, are currently the most widely used class of antibiotics. This study focused on the chemical reactivity of five- and six-membered ring systems attached to the β-lactam ring. The ring strain energy (RSE), force constant (FC) of amide (C-N), acylation transition states and second-order perturbation stabilization energies of 13 basic structural units of β-lactam derivatives were computed using the M06-2X and G3/B3LYP multistep method. In the ring strain calculations, an isodesmic reaction scheme was used to obtain the total energies. RSE is relatively greater in the five-(1a-2c) compared to the six-membered ring systems except for 4b, which gives a RSE that is comparable to five-membered ring lactams. These variations were also observed in the calculated inter-atomic amide bond distances (C-N), which is why the six-membered ring lactams C-N bond are more rigid than those with five-membered ring lactams. The calculated ΔG# values from the acylation reaction of the lactams (involving the S-H group of the cysteine active residue from L,D transpeptidase 2) revealed a faster rate of C-N cleavage in the five-membered ring lactams especially in the 1-2 derivatives (17.58 kcal mol-1 ). This observation is also reflected in the calculated amide bond force constant (1.26 mDyn/A) indicating a weaker bond strength, suggesting that electronic factors (electron delocalization) play more of a role on reactivity of the β-lactam ring, than ring strain.
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Affiliation(s)
- Collins U Ibeji
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa.,Department of Pure and Industrial Chemistry, Faculty of Physical Sciences, University of Nigeria, Nsukka, 410001, Enugu State, Nigeria
| | - Monsurat M Lawal
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa
| | - Gideon F Tolufashe
- 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
| | - Tricia Naicker
- 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
| | - Gyanu Lamichhane
- Center for Tuberculosis Research, Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Hendrik G Kruger
- 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
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10
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Nizami B, Sarasia EM, Momin MIK, Honarparvar B. Estrogenic Active Stilbene Derivatives as Anti-Cancer Agents: A DFT and QSAR Study. IEEE/ACM Trans Comput Biol Bioinform 2019; 16:560-568. [PMID: 29990200 DOI: 10.1109/tcbb.2017.2779505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Exploring different quantum chemical quantities for lead compounds is an ongoing approach in identifying crucial structural activity related features that are contributing into their biological activities. Herein, activity-related quantum chemical calculations were performed for the selected estrogenic stilbene derivatives using density functional theory (DFT) with B3LYP functional and 6-311++G** basis set. In addition, specific activity-related geometry-independent drug-like properties are discussed for these derivatives. To obtain the mathematical model that correlates the chemical descriptors with their measured estrogenic activities, the quantitative structure activity relationship (QSAR) is established using multiple linear regression (MLR) and support vector regression (SVR) methods. Satisfactory fit with a reasonable regression correlation coefficient (${\rm{R}}^{2}= 0.78$R2=0.78) between predicted and experimental $pEC_{50}$pEC50 values is observed using MLR method. The present study identifies the essential physicochemical descriptors that effectively contribute in the estrogenic activity. The applied approach provides helpful insight into the designing novel estrogenic agents with improved anticancer activities.
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Honarparvar B, Kanchi S, Bisetty K. Theoretical insights into the competitive metal bioaffinity of lactoferrin as a metal ion carrier: a DFT study. NEW J CHEM 2019. [DOI: 10.1039/c9nj03786a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Metal–protein complexes, specifically lactoferrin (Lf), an iron-binding glycoprotein found naturally in milk and several other body fluids play a pivotal role in all living organisms.
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Affiliation(s)
- Bahareh Honarparvar
- Department of Chemistry
- Durban University of Technology
- Durban 4000
- South Africa
| | - Suvardhan Kanchi
- Department of Chemistry
- Durban University of Technology
- Durban 4000
- South Africa
| | - Krishna Bisetty
- Department of Chemistry
- Durban University of Technology
- Durban 4000
- South Africa
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Akher FB, Farrokhzadeh A, Honarparvar B. Effect of substituent and π-stacking interaction on the metal chelation ability of 7-subestituted 2-oxyisoquinoline-1,3(2H,4H)-diones as an HIV integrase inhibitor: A DFT study. J Mol Struct 2019. [DOI: 10.1016/j.molstruc.2018.08.042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Tolufashe GF, Halder AK, Ibeji CU, Lawal MM, Ntombela T, Govender T, Maguire GEM, Lamichhane G, Kruger HG, Honarparvar B. Inhibition of Mycobacterium tuberculosis
L,D-Transpeptidase 5 by Carbapenems: MD and QM/MM Mechanistic Studies. ChemistrySelect 2018. [DOI: 10.1002/slct.201803184] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Gideon F. Tolufashe
- Catalysis and Peptide Research Unit; School of Health Sciences; University of KwaZulu-Natal; Durban 4001 South Africa
| | - Amit K. Halder
- Catalysis and Peptide Research Unit; School of Health Sciences; University of KwaZulu-Natal; Durban 4001 South Africa
| | - Collins U. Ibeji
- Catalysis and Peptide Research Unit; School of Health Sciences; University of KwaZulu-Natal; Durban 4001 South Africa
| | - Monsurat M. Lawal
- Catalysis and Peptide Research Unit; School of Health Sciences; University of KwaZulu-Natal; Durban 4001 South Africa
| | - Thandokuhle Ntombela
- Catalysis and Peptide Research Unit; School of Health Sciences; University of KwaZulu-Natal; Durban 4001 South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit; School of Health Sciences; University of KwaZulu-Natal; Durban 4001 South Africa
| | - Glenn E. M. Maguire
- Catalysis and Peptide Research Unit; School of Health Sciences; University of KwaZulu-Natal; Durban 4001 South Africa
- School of Chemistry and Physics; University of KwaZulu-Natal; 4001 Durban South Africa
| | - Gyanu Lamichhane
- Division of Infectious Diseases; School of Medicine; Johns Hopkins University; Baltimore MD 21205 USA
| | - Hendrik G. Kruger
- Catalysis and Peptide Research Unit; School of Health Sciences; University of KwaZulu-Natal; Durban 4001 South Africa
| | - Bahareh Honarparvar
- Catalysis and Peptide Research Unit; School of Health Sciences; University of KwaZulu-Natal; Durban 4001 South Africa
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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] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Ibeji CU, Tolufashe GF, Ntombela T, Govender T, Maguire GEM, Lamichhane G, Kruger HG, Honarparvar B. The catalytic role of water in the binding site of l,d-transpeptidase 2 within acylation mechanism: A QM/MM (ONIOM) modelling. Tuberculosis (Edinb) 2018; 113:222-230. [PMID: 30514506 DOI: 10.1016/j.tube.2018.10.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 10/11/2018] [Accepted: 10/14/2018] [Indexed: 01/13/2023]
Abstract
Mycobacterium tuberculosis is the causative agent of Tuberculosis. Formation of 3 → 3 crosslinks in the peptidoglycan layer of M. tuberculosis is catalyzed by l,d-transpeptidases. These enzymes can confer resistance against classical β-lactams that inhibit enzymes that generate 4 → 3 peptidoglycan crosslinks. The focus of this study is to investigate the catalytic role of water molecules in the acylation mechanism of the β-lactam ring within two models; 4- and 6-membered ring systems using two-layered our Own N-layer integrated Molecular Mechanics ONIOM (B3LYP/6-311++G(2d,2p): AMBER) model. The obtained thermochemical parameters revealed that the 6-membered ring model best describes the inhibition mechanism of acylation which indicates the role of water in the preference of 6-membered ring reaction pathway. This finding is in accordance with experimental data for the rate-limiting step of cysteine protease with the same class of inhibitor and binding affinity for both inhibitors. As expected, the ΔG# results also reveal that the 6-membered ring reaction pathway is the most favourable. The electrostatic potential (ESP) and the natural bond orbital analysis (NBO) showed stronger interactions in 6-membered ring transition state (TS-6) mechanism involving water in the active site of the enzyme. This study could be helpful in the development of novel antibiotics against l,d-transpeptidase.
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Affiliation(s)
- Collins U Ibeji
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa; Department of Pure and Industrial Chemistry, Faculty of Physical Sciences, University of Nigeria, Nsukka, 410001, Enugu State, Nigeria
| | - Gideon F Tolufashe
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa
| | - Thandokuhle Ntombela
- 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; School of Chemistry and Physics, University of KwaZulu-Natal, Durban, 4041, South Africa
| | - Gyanu Lamichhane
- Center for Tuberculosis Research, Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, MD, 21287, USA
| | - Hendrik G Kruger
- 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.
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Maphumulo SI, Halder AK, Govender T, Maseko S, Maguire GEM, Honarparvar B, Kruger HG. Exploring the flap dynamics of the South African HIV subtype C protease in presence of FDA-approved inhibitors: MD study. Chem Biol Drug Des 2018; 92:1899-1913. [PMID: 30003668 DOI: 10.1111/cbdd.13364] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 07/09/2018] [Indexed: 01/01/2023]
Abstract
HIV-1 protease (HIV PR) is considered as one of the most attractive targets for the treatment of HIV and the impact of flap dynamics of HIV PR on the binding affinities of protease inhibitors (PIs) is a crucial ongoing research field. Recently, our research group evaluated the binding affinities of different FDA approved PIs against the South African HIV-1 subtype C (C-SA) protease (PR). The CSA-HIV PR displayed weaker binding affinity for most of the clinical PIs compared to HIV-1 B subtype for West and Central Europe, the Americas. In the current work, the flap dynamics of four different systems of HIV-1 C-SA PR complexed to FDA approved second generation PIs and its impact on binding was explored over the molecular dynamic trajectories. It was observed that the interactions of the selected drugs with the binding site residues of the protease may not be the major contributor for affinity towards PIs. Various post-MD analyses were performed, also entropic contributions, solvation free energies and hydrophobic core formation interactions were studied to assess how the flap dynamics of C-SA PR which is affected by such factors. From these contributions, large van der Waals interactions and low solvation free energies were found to be major factors for the higher activity of ATV against C-SA HIV PR. Furthermore, a comparatively stable hydrophobic core may be responsible for higher stability of the PR flaps of the ATV complex. The outcome of this study provides significant guidance to how the flap dynamics of C-SA PR is affected by various factors as a result of the binding affinity of various protease inhibitors. It will also assist with the design of potent inhibitors against C-SA HIV PR that apart from binding in the active site of PR can interacts with the flaps to prevent opening of the flaps resulting in inactivation of the protease.
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Affiliation(s)
- Siyabonga I Maphumulo
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Amit K Halder
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Sibusiso Maseko
- 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
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
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17
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Ntombela T, Fakhar Z, Ibeji CU, Govender T, Maguire GEM, Lamichhane G, Kruger HG, Honarparvar B. Molecular insight on the non-covalent interactions between carbapenems and L,D-transpeptidase 2 from Mycobacterium tuberculosis: ONIOM study. J Comput Aided Mol Des 2018; 32:687-701. [PMID: 29845435 DOI: 10.1007/s10822-018-0121-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 05/14/2018] [Indexed: 12/01/2022]
Abstract
Tuberculosis remains a dreadful disease that has claimed many human lives worldwide and elimination of the causative agent Mycobacterium tuberculosis also remains elusive. Multidrug-resistant TB is rapidly increasing worldwide; therefore, there is an urgent need for improving the current antibiotics and novel drug targets to successfully curb the TB burden. L,D-Transpeptidase 2 is an essential protein in Mtb that is responsible for virulence and growth during the chronic stage of the disease. Both D,D- and L,D-transpeptidases are inhibited concurrently to eradicate the bacterium. It was recently discovered that classic penicillins only inhibit D,D-transpeptidases, while L,D-transpeptidases are blocked by carbapenems. This has contributed to drug resistance and persistence of tuberculosis. Herein, a hybrid two-layered ONIOM (B3LYP/6-31G+(d): AMBER) model was used to extensively investigate the binding interactions of LdtMt2 complexed with four carbapenems (biapenem, imipenem, meropenem, and tebipenem) to ascertain molecular insight of the drug-enzyme complexation event. In the studied complexes, the carbapenems together with catalytic triad active site residues of LdtMt2 (His187, Ser188 and Cys205) were treated at with QM [B3LYP/6-31+G(d)], while the remaining part of the complexes were treated at MM level (AMBER force field). The resulting Gibbs free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) for all complexes showed that the carbapenems exhibit reasonable binding interactions towards LdtMt2. Increasing the number of amino acid residues that form hydrogen bond interactions in the QM layer showed significant impact in binding interaction energy differences and the stabilities of the carbapenems inside the active pocket of LdtMt2. The theoretical binding free energies obtained in this study reflect the same trend of the experimental observations. The electrostatic, hydrogen bonding and Van der Waals interactions between the carbapenems and LdtMt2 were also assessed. To further examine the nature of intermolecular interactions for carbapenem-LdtMt2 complexes, AIM and NBO analysis were performed for the QM region (carbapenems and the active residues of LdtMt2) of the complexes. These analyses revealed that the hydrogen bond interactions and charge transfer from the bonding to anti-bonding orbitals between catalytic residues of the enzyme and selected ligands enhances the binding and stability of carbapenem-LdtMt2 complexes. The two-layered ONIOM (B3LYP/6-31+G(d): Amber) model was used to evaluate the efficacy of FDA approved carbapenems antibiotics towards LdtMt2.
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Affiliation(s)
- Thandokuhle Ntombela
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Zeynab Fakhar
- Department of Chemistry, Faculty of Natural and Agricultural Sciences, University of Pretoria, Lynnwood Road, Hatfield 0002, Pretoria, South Africa
| | - Collins U Ibeji
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Glenn E M Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa.,School of Chemistry and Physics, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Gyanu Lamichhane
- Division of Infectious Diseases, School of Medicine, Center of Tuberculosis Research, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa.
| | - Bahareh Honarparvar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa.
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18
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Sanusi ZK, Govender T, Maguire GEM, Maseko SB, Lin J, Kruger HG, Honarparvar B. An insight to the molecular interactions of the FDA approved HIV PR drugs against L38L↑N↑L PR mutant. J Comput Aided Mol Des 2018; 32:459-471. [PMID: 29397520 DOI: 10.1007/s10822-018-0099-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 01/16/2018] [Indexed: 01/12/2023]
Abstract
The aspartate protease of the human immune deficiency type-1 virus (HIV-1) has become a crucial antiviral target in which many useful antiretroviral inhibitors have been developed. However, it seems the emergence of new HIV-1 PR mutations enhances drug resistance, hence, the available FDA approved drugs show less activity towards the protease. A mutation and insertion designated L38L↑N↑L PR was recently reported from subtype of C-SA HIV-1. An integrated two-layered ONIOM (QM:MM) method was employed in this study to examine the binding affinities of the nine HIV PR inhibitors against this mutant. The computed binding free energies as well as experimental data revealed a reduced inhibitory activity towards the L38L↑N↑L PR in comparison with subtype C-SA HIV-1 PR. This observation suggests that the insertion and mutations significantly affect the binding affinities or characteristics of the HIV PIs and/or parent PR. The same trend for the computational binding free energies was observed for eight of the nine inhibitors with respect to the experimental binding free energies. The outcome of this study shows that ONIOM method can be used as a reliable computational approach to rationalize lead compounds against specific targets. The nature of the intermolecular interactions in terms of the host-guest hydrogen bond interactions is discussed using the atoms in molecules (AIM) analysis. Natural bond orbital analysis was also used to determine the extent of charge transfer between the QM region of the L38L↑N↑L PR enzyme and FDA approved drugs. AIM analysis showed that the interaction between the QM region of the L38L↑N↑L PR and FDA approved drugs are electrostatic dominant, the bond stability computed from the NBO analysis supports the results from the AIM application. Future studies will focus on the improvement of the computational model by considering explicit water molecules in the active pocket. We believe that this approach has the potential to provide information that will aid in the design of much improved HIV-1 PR antiviral drugs.
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Affiliation(s)
- Zainab K Sanusi
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Glenn E M Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa.,School of Chemistry and Physics, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Sibusiso B Maseko
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Johnson Lin
- School of Life Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa.
| | - Bahareh Honarparvar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa.
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Sharma D, Sabela MI, Kanchi S, Bisetty K, Skelton AA, Honarparvar B. Green synthesis, characterization and electrochemical sensing of silymarin by ZnO nanoparticles: Experimental and DFT studies. J Electroanal Chem (Lausanne) 2018. [DOI: 10.1016/j.jelechem.2017.11.039] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Adeowo FY, Honarparvar B, Skelton AA. Density Functional Theory Study on the Complexation of NOTA as a Bifunctional Chelator with Radiometal Ions. J Phys Chem A 2017; 121:6054-6062. [PMID: 28737914 DOI: 10.1021/acs.jpca.7b01017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
1,4,7-Triazacyclononane-1,4,7-triacetic acid (NOTA) is a key bifunctional chelator utilized for the complexation of metal ions in radiopharmaceutical applications; the ability of these chelators depends on the strength of their binding with ions. The focus of the present work is to evaluate the complexation of Cu2+, Ga3+, Sc3+, and In3+ radiometal ions with NOTA using density functional theory (B3LYP functional) and 6-311+G(2d,2p)/DGDZVP basis sets. The significant role of ion-water interactions in the chelation interaction energies in solution reflects the competition between ion-water and NOTA-ion interaction in the chelation process. There is reasonable agreement between experimental and theoretical binding constants, geometries, and 1H NMR chemical shifts. Chelation interaction energies, Gibbs free energies, and entropies in solution show that the NOTA-Ga3+ and NOTA-Cu2+ are the most and least stable complexes, respectively. The natural atomic charges and second order perturbation analysis reveal charge transfer between NOTA and radiometal ions. The theoretical 1H NMR chemical shifts of NOTA are in good agreement with experiment; these values are influenced by the presence of the ions, which have a deshielding effect on the protons of NOTA. Global scalar properties such as EHOMO/ELUMO, ΔELUMO-HOMO, and chemical hardness/softness confirm that the NOTA-Cu2+ complex, which has a singly occupied molecular orbital, has the lowest ΔELUMO-HOMO value, the least chemical hardness, and the highest chemical softness. The significant variation of the hardness and ΔELUMO-HOMO values of the complexes can be attributed to the different positions of the metal ions on the periodic table. This study affirms that, among the radiometal ions, Ga3+ can be used to effectively radiolabel NOTA chelator for radiopharmaceutical usage as it binds most stably with NOTA.
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Affiliation(s)
- F Y Adeowo
- School of Health Sciences, Discipline of Pharmacy, University of KwaZulu-Natal , Durban 4001, South Africa
| | - B Honarparvar
- School of Health Sciences, Discipline of Pharmacy, University of KwaZulu-Natal , Durban 4001, South Africa
| | - A A Skelton
- School of Health Sciences, Discipline of Pharmacy, University of KwaZulu-Natal , Durban 4001, South Africa
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Nizami B, Sydow D, Wolber G, Honarparvar B. Molecular insight on the binding of NNRTI to K103N mutated HIV-1 RT: molecular dynamics simulations and dynamic pharmacophore analysis. Mol Biosyst 2017; 12:3385-3395. [PMID: 27722739 DOI: 10.1039/c6mb00428h] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Regardless of advances in anti-HIV therapy, HIV infection remains an immense challenge due to the rapid onset of mutation instigating drug resistance. Rilpivirine is a second generation di-aryl pyrimidine (DAPY) derivative, known to effectively inhibit wild-type (WT) as well as various mutant HIV-1 reverse transcriptase (RT). In this study, a cumulative 240 ns of molecular dynamic (MD) simulations of WT HIV-1 RT and its corresponding K103N mutated form, complexed with rilpivirine, were performed in solution. Conformational analysis of the NNRTI inside the binding pocket (NNIBP) revealed the ability of rilpivirine to adopt different conformations, which is possibly the reason for its reasonable activity against mutant HIV-1 RT. Binding free energy (MM-PB/GB SA) calculations of rilpivirine with mutant HIV-1 RT are in agreement with experimental data. The dynamics of interaction patterns were investigated based on the MD simulations using dynophores, a novel approach for MD-based ligand-target interaction mapping. The results from this interaction profile analysis suggest an alternate interaction between the linker N atom of rilpivirine and Lys 101, potentially providing the stability for ligand binding. PCA analysis and per residue fluctuation has highlighted the significant role of flexible thumb and finger sub-domains of RT in its biological activity. This study investigated the underlying reason for rilpivirine's improved inhibitory profile against mutant RT, which could be helpful to understand the molecular basis of HIV-1 RT drug resistance and design novel NNRTIs with improved drug resistance tolerance.
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Affiliation(s)
- Bilal Nizami
- School of Pharmacy and Pharmacology, University of KwaZulu-Natal, Durban 4000, South Africa.
| | - Dominique Sydow
- Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14175 Berlin, Germany
| | - Gerhard Wolber
- Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14175 Berlin, Germany
| | - Bahareh Honarparvar
- School of Pharmacy and Pharmacology, University of KwaZulu-Natal, Durban 4000, South Africa.
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22
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Frimpong E, Skelton AA, Honarparvar B. DFT study of the interaction between DOTA chelator and competitive alkali metal ions. J Mol Graph Model 2017; 76:70-76. [PMID: 28711759 DOI: 10.1016/j.jmgm.2017.06.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 06/23/2017] [Accepted: 06/26/2017] [Indexed: 10/19/2022]
Abstract
1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetracetic acid (DOTA) is an important chelator for radiolabeling of pharmaceuticals. The ability of alkali metals found in the body to complex with DOTA and compete with radio metal ions can alter the radiolabeling process. Non-covalent interactions between DOTA complexed with alkali metals Li+, Na+, K+ and Rb+, are investigated with density functional theory using B3LYP and ωB97XD functionals. Conformational possibilities of DOTA were explored with a varying number of carboxylic pendant arms of DOTA in close proximity to the ions. It is found that the case in which four arms of DOTA are interacting with ions is more stable than other conformations. The objective of this study is to explore the electronic structure properties upon complexation of alkali metals Li+ Na+, K+ and Rb+ with a DOTA chelator. Interaction energies, relaxation energies, entropies, Gibbs free energies and enthalpies show that the stability of DOTA, complexed with alkali metals decreases down the group of the periodic table. Implicit water solvation affects the complexation of DOTA-ions leading to decreases in the stability of the complexes. NBO analysis through the natural population charges and the second order perturbation theory, revealed a charge transfer between DOTA and alkali metals. Conceptual DFT-based properties such as HOMO/LUMO energies, ΔEHOMO-LUMO and chemical hardness and softness indicated a decrease in the chemical stability of DOTA-alkali metal complexes down the alkali metal series. This study serves as a guide to researchers in the field of organometallic chelators, particularly, radiopharmaceuticals in finding the efficient optimal match between chelators and various metal ions.
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Affiliation(s)
- E Frimpong
- School of Pharmacy and Pharmacology, University of KwaZulu-Natal, Durban 4001, South Africa
| | - A A Skelton
- School of Pharmacy and Pharmacology, University of KwaZulu-Natal, Durban 4001, South Africa.
| | - B Honarparvar
- School of Pharmacy and Pharmacology, University of KwaZulu-Natal, Durban 4001, South Africa.
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Sanusi ZK, Govender T, Maguire GEM, Maseko SB, Lin J, Kruger HG, Honarparvar B. Investigation of the binding free energies of FDA approved drugs against subtype B and C-SA HIV PR: ONIOM approach. J Mol Graph Model 2017; 76:77-85. [PMID: 28711760 DOI: 10.1016/j.jmgm.2017.06.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 06/08/2017] [Accepted: 06/09/2017] [Indexed: 01/15/2023]
Abstract
Human immune virus subtype C is the most widely spread HIV subtype in Sub-Sahara Africa and South Africa. A profound structural insight on finding potential lead compounds is therefore necessary for drug discovery. The focus of this study is to rationalize the nine Food and Drugs Administration (FDA) HIV antiviral drugs complexed to subtype B and C-SA PR using ONIOM approach. To achieve this, an integrated two-layered ONIOM model was used to optimize the geometrics of the FDA approved HIV-1 PR inhibitors for subtype B. In our hybrid ONIOM model, the HIV-1 PR inhibitors as well as the ASP 25/25' catalytic active residues were treated at high level quantum mechanics (QM) theory using B3LYP/6-31G(d), and the remaining HIV PR residues were considered using the AMBER force field. The experimental binding energies of the PR inhibitors were compared to the ONIOM calculated results. The theoretical binding free energies (?Gbind) for subtype B follow a similar trend to the experimental results, with one exemption. The computational model was less suitable for C-SA PR. Analysis of the results provided valuable information about the shortcomings of this approach. Future studies will focus on the improvement of the computational model by considering explicit water molecules in the active pocket. We believe that this approach has the potential to provide much improved binding energies for complex enzyme drug interactions.
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Affiliation(s)
- Z K Sanusi
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4001, South Africa
| | - T Govender
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4001, South Africa
| | - G E M Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4001, South Africa; School of Chemistry and Physics, University of KwaZulu-Natal, 4001 Durban, South Africa
| | - S B Maseko
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4001, South Africa
| | - J Lin
- School of Life Sciences, University of KwaZulu-Natal, Durban 4001, South Africa
| | - H G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4001, South Africa.
| | - B Honarparvar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban 4001, South Africa.
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Fakhar Z, Govender T, Maguire GEM, Lamichhane G, Walker RC, Kruger HG, Honarparvar B. Differential flap dynamics in l,d-transpeptidase2 from mycobacterium tuberculosis revealed by molecular dynamics. Mol Biosyst 2017; 13:1223-1234. [PMID: 28480928 DOI: 10.1039/c7mb00110j] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Despite the advances in tuberculosis treatment, TB is still one the most deadly infectious diseases and remains a major global health quandary. Mycobacterium tuberculosis (Mtb) is the only known mycobacterium with a high content of 3→3 crosslinks in the biosynthesis of peptidoglycan, which is negligible in most bacterial species. An Mtb lacking LdtMt2 leads to alteration of the colony morphology and loss of virulence which makes this enzyme an attractive target. Regardless of the vital role of LdtMt2 for cell wall survival, the impact of ligand binding on the dynamics of the β-hairpin flap is still unknown. Understanding the structural and dynamical behaviour of the flap regions provides clear insight into the design of the effective inhibitors against LdtMt2. Carbapenems, an specific class of β-lactam family, have been shown to inactivate this enzyme. Herein a comprehensive investigation of the flap dynamics of LdtMt2 complex with substrate and three carbapenems namely, ertapenem, imipenem and meropenem is discussed and analyzed for the first account using 140 ns molecular dynamics simulations. The structural features (RMSD, RMSF and Rg) derived by MD trajectories were analyzed. Distance analysis, particularly tip-tip SER135-ASN167 index, identified conformational changes in terms of flap opening and closure within binding process. Principal component analysis (PCA) was employed to qualitatively understand the divergent effects of different inhibitors on the dominant motion of each residue. To probe different internal dynamics induced by ligand binding, dynamic cross-correlation marix (DCCM) analysis was used. The binding free energies of the selected complexes were assessed using MM-GBSA method and per residue free energy decomposition analysis were performed to characterize the contribution of the key residues to the total binding free energies.
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Affiliation(s)
- Zeynab Fakhar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa.
| | - Thavendran Govender
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa.
| | - Glenn E M Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa. and School of Chemistry and Physics, University of KwaZulu-Natal, 4001, Durban, South Africa
| | - Gyanu Lamichhane
- Center for Tuberculosis Research, Division of Infectious Diseases, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Ross C Walker
- GlaxoSmithKline PLC, 1250 S. Collegeville Rd., Collegeville, PA 19426, USA and Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Hendrik G Kruger
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa.
| | - Bahareh Honarparvar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4001, South Africa.
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Fakhar Z, Govender T, Lamichhane G, Maguire GE, Kruger HG, Honarparvar B. Computational model for the acylation step of the β-lactam ring: Potential application for l,d-transpeptidase 2 in mycobacterium tuberculosis. J Mol Struct 2017. [DOI: 10.1016/j.molstruc.2016.08.049] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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I. K. Momin M, A. Koorbanally N, Honarparvar B. Imidazole-based Derivatives as Potential Anti-platelet Inhibitors: DFT and Molecular Docking Study. LETT DRUG DES DISCOV 2016. [DOI: 10.2174/1570180813666160517162937] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Lawal MM, Govender T, Maguire GEM, Honarparvar B, Kruger HG. Mechanistic investigation of the uncatalyzed esterification reaction of acetic acid and acid halides with methanol: a DFT study. J Mol Model 2016; 22:235. [PMID: 27604278 DOI: 10.1007/s00894-016-3084-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 08/05/2016] [Indexed: 11/29/2022]
Abstract
Implementation of catalysts to drive reactions from reactants to products remains a burden to synthetic and organic chemists. In spite of investigations into the kinetics and mechanism of catalyzed esterification reactions, less effort has been made to explore the possibility of an uncatalyzed esterification process. Therefore, a comprehensive mechanistic perspective for the uncatalyzed mechanism at the molecular level is presented. Herein, we describe the non-catalyzed esterification reaction of acetic acid and its halide derivatives (XAc, where X= OH, F, Cl, Br, I) with methanol (MeOH) through a concerted process. The reaction in vacuum and methanol was performed using the density functional theory (DFT) method at M06-2X level with def2-TZVP basis set after a careful literature survey and computations. Esterification through cyclic 4- or 6-membered transition state structures in one- or two-step concerted mechanisms were investigated. The present study outlines the possible cyclic geometry conformations that may occur during experiments at simple ratio of reactants. The free energy of activation for acetic acid and acetyl chloride are 36 kcal mol(-1) and 21 kcal mol(-1), respectively. These are in good agreement with available experimental results from the literature. The selected quantum chemical descriptors proved to be useful tools in chemical reactivity prediction for the reaction mechanism. This quantum mechanics study can serve as a necessary step towards revisiting uncatalyzed reaction mechanisms in some classical organic reactions.
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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
| | - 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.,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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Goodarzi M, Coelho LDS, Honarparvar B, Ortiz EV, Duchowicz PR. Application of quantitative structure-property relationship analysis to estimate the vapor pressure of pesticides. Ecotoxicol Environ Saf 2016; 128:52-60. [PMID: 26890190 DOI: 10.1016/j.ecoenv.2016.01.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 01/23/2016] [Accepted: 01/25/2016] [Indexed: 06/05/2023]
Abstract
The application of molecular descriptors in describing Quantitative Structure Property Relationships (QSPR) for the estimation of vapor pressure (VP) of pesticides is of ongoing interest. In this study, QSPR models were developed using multiple linear regression (MLR) methods to predict the vapor pressure values of 162 pesticides. Several feature selection methods, namely the replacement method (RM), genetic algorithms (GA), stepwise regression (SR) and forward selection (FS), were used to select the most relevant molecular descriptors from a pool of variables. The optimum subset of molecular descriptors was used to build a QSPR model to estimate the vapor pressures of the selected pesticides. The Replacement Method improved the predictive ability of vapor pressures and was more reliable for the feature selection of these selected pesticides. The results provided satisfactory MLR models that had a satisfactory predictive ability, and will be important for predicting vapor pressure values for compounds with unknown values. This study may open new opportunities for designing and developing new pesticide.
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Affiliation(s)
- Mohammad Goodarzi
- Department of Biosystems, Faculty of Bioscience Engineering, Katholieke Universiteit Leuven - KULeuven, Kasteelpark Arenberg 30, B-3001 Heverlee, Belgium
| | - Leandro dos Santos Coelho
- Department of Electrical Engineering, Federal University of Parana (UFPR), Rua Cel. Francisco Heraclito dos Santos, 100, 81531-980 Curitiba, PR, Brazil; Industrial and Systems Engineering Graduate Program (PPGEPS), Pontifical Catholic University of Parana (PUCPR), Imaculada Conceição, 1155, 80215-901 Curitiba, PR, Brazil
| | - Bahareh Honarparvar
- School of Pharmacy and Pharmacology, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Erlinda V Ortiz
- IMCoDeG (CONICET), Fac. de Tecnología y Cs. Aplicadas, Universidad Nacional de Catamarca, Maximio Victoria 55, Catamarca, Argentina
| | - Pablo R Duchowicz
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas INIFTA (CCT La Plata-CONICET, UNLP), Diag. 113 y 64, Sucursal 4, C.C. 16, 1900 La Plata, Argentina.
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Fakhar Z, Naiker S, Alves CN, Govender T, Maguire GEM, Lameira J, Lamichhane G, Kruger HG, Honarparvar B. A comparative modeling and molecular docking study on Mycobacterium tuberculosis targets involved in peptidoglycan biosynthesis. J Biomol Struct Dyn 2016; 34:2399-417. [PMID: 26612108 DOI: 10.1080/07391102.2015.1117397] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
An alarming rise of multidrug-resistant Mycobacterium tuberculosis strains and the continuous high global morbidity of tuberculosis have reinvigorated the need to identify novel targets to combat the disease. The enzymes that catalyze the biosynthesis of peptidoglycan in M. tuberculosis are essential and noteworthy therapeutic targets. In this study, the biochemical function and homology modeling of MurI, MurG, MraY, DapE, DapA, Alr, and Ddl enzymes of the CDC1551 M. tuberculosis strain involved in the biosynthesis of peptidoglycan cell wall are reported. Generation of the 3D structures was achieved with Modeller 9.13. To assess the structural quality of the obtained homology modeled targets, the models were validated using PROCHECK, PDBsum, QMEAN, and ERRAT scores. Molecular dynamics simulations were performed to calculate root mean square deviation (RMSD) and radius of gyration (Rg) of MurI and MurG target proteins and their corresponding templates. For further model validation, RMSD and Rg for selected targets/templates were investigated to compare the close proximity of their dynamic behavior in terms of protein stability and average distances. To identify the potential binding mode required for molecular docking, binding site information of all modeled targets was obtained using two prediction algorithms. A docking study was performed for MurI to determine the potential mode of interaction between the inhibitor and the active site residues. This study presents the first accounts of the 3D structural information for the selected M. tuberculosis targets involved in peptidoglycan biosynthesis.
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Affiliation(s)
- Zeynab Fakhar
- a Catalysis and Peptide Research Unit, School of Health Sciences , University of KwaZulu-Natal , Durban 4001 , South Africa
| | - Suhashni Naiker
- a Catalysis and Peptide Research Unit, School of Health Sciences , University of KwaZulu-Natal , Durban 4001 , South Africa
| | - Claudio N Alves
- b Laboratório de Planejamento de Fármacos, Instituto de Ciências Exatas e Naturais , Instituto de Ciências Biológicas, Universidade Federal do Pará , CEP 66075-110, Belém , Pará , Brazil
| | - Thavendran Govender
- a Catalysis and Peptide Research Unit, School of Health Sciences , University of KwaZulu-Natal , Durban 4001 , South Africa
| | - Glenn E M Maguire
- a Catalysis and Peptide Research Unit, School of Health Sciences , University of KwaZulu-Natal , Durban 4001 , South Africa.,c School of Chemistry and Physics , University of KwaZulu-Natal , 4001 Durban , South Africa
| | - Jeronimo Lameira
- b Laboratório de Planejamento de Fármacos, Instituto de Ciências Exatas e Naturais , Instituto de Ciências Biológicas, Universidade Federal do Pará , CEP 66075-110, Belém , Pará , Brazil
| | - Gyanu Lamichhane
- d Division of Infectious Diseases, Center for Tuberculosis Research , Johns Hopkins University School of Medicine , Baltimore , MD 21205 , USA
| | - Hendrik G Kruger
- a Catalysis and Peptide Research Unit, School of Health Sciences , University of KwaZulu-Natal , Durban 4001 , South Africa
| | - Bahareh Honarparvar
- a Catalysis and Peptide Research Unit, School of Health Sciences , University of KwaZulu-Natal , Durban 4001 , South Africa
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Abstract
This work investigates NOTA–alkali metal (Li+, Na+ and K+ and Rb+) complexation using density functional theory.
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Affiliation(s)
- F. Y. Adeowo
- School of Health Sciences
- School of Pharmacy and Pharmacology
- Discipline of Pharmacy
- University of KwaZulu-Natal
- Durban 4001
| | - B. Honarparvar
- School of Health Sciences
- School of Pharmacy and Pharmacology
- Discipline of Pharmacy
- University of KwaZulu-Natal
- Durban 4001
| | - A. A. Skelton
- School of Health Sciences
- School of Pharmacy and Pharmacology
- Discipline of Pharmacy
- University of KwaZulu-Natal
- Durban 4001
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Honarparvar B, Skelton AA. Molecular dynamics simulation and conformational analysis of some catalytically active peptides. J Mol Model 2015; 21:100. [DOI: 10.1007/s00894-015-2645-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 03/09/2015] [Indexed: 01/10/2023]
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Honarparvar B, Pawar SA, Alves CN, Lameira J, Maguire GE, Silva JRA, Govender T, Kruger HG. Pentacycloundecane lactam vs lactone norstatine type protease HIV inhibitors: binding energy calculations and DFT study. J Biomed Sci 2015; 22:15. [PMID: 25889635 PMCID: PMC4387594 DOI: 10.1186/s12929-015-0115-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 01/16/2015] [Indexed: 01/12/2023] Open
Abstract
Background Novel pentacycloundecane (PCU)-lactone-CO-EAIS peptide inhibitors were designed, synthesized, and evaluated against wild-type C-South African (C-SA) HIV-1 protease. Three compounds are reported herein, two of which displayed IC50 values of less than 1.00 μM. A comparative MM-PB(GB)SA binding free energy of solvation values of PCU-lactam and lactone models and their enantiomers as well as the PCU-lactam-NH-EAIS and lactone-CO-EAIS peptide inhibitors and their corresponding diastereomers complexed with South African HIV protease (C-SA) was performed. This will enable us to rationalize the considerable difference between inhibitory concentration (IC50) of PCU-lactam-NH-EAIS and PCU-lactone-CO-EAIS peptides. Results The PCU-lactam model exhibited more negative calculated binding free energies of solvation than the PCU-lactone model. The same trend was observed for the PCU-peptide inhibitors, which correspond to the experimental activities for the PCU-lactam-NH-EAIS peptide (IC50 = 0.076 μM) and the PCU-lactone-CO-EAIS peptide inhibitors (IC50 = 0.850 μM). Furthermore, a density functional theory (DFT) study on the natural atomic charges of the nitrogen and oxygen atoms of the three PCU-lactam, PCU-lactim and PCU-lactone models were performed using natural bond orbital (NBO) analysis. Electrostatic potential maps were also used to visualize the electron density around electron-rich regions. The asymmetry parameter (η) and quadrupole coupling constant (χ) values of the nitrogen and oxygen nuclei of the model compounds were calculated at the same level of theory. Electronic molecular properties including polarizability and electric dipole moments were also calculated and compared. The Gibbs theoretical free solvation energies of solvation (∆Gsolv) were also considered. Conclusions A general trend is observed that the lactam species appears to have a larger negative charge distribution around the heteroatoms, larger quadrupole constant, dipole moment and better solvation energy, in comparison to the PCU-lactone model. It can be argued that these characteristics will ensure better eletronic interaction between the lactam and the receptor, corresponding to the observed HIV protease activities in terms of experimental IC50 data. Electronic supplementary material The online version of this article (doi:10.1186/s12929-015-0115-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Bahareh Honarparvar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa.
| | - Sachin A Pawar
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa.
| | - Cláudio Nahum Alves
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais, Universidade Federal do Pará, CP 11101, 66075-110, Belém, PA, Brazil.
| | - Jerônimo Lameira
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais, Universidade Federal do Pará, CP 11101, 66075-110, Belém, PA, Brazil.
| | - Glenn Em Maguire
- Catalysis and Peptide Research Unit, School of Health Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa.
| | - José Rogério A Silva
- Laboratório de Planejamento e Desenvolvimento de Fármacos, Instituto de Ciências Exatas e Naturais, Universidade Federal do Pará, CP 11101, 66075-110, Belém, PA, Brazil.
| | - Thavendran Govender
- 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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Md. Abdur Rauf S, Arvidsson PI, Albericio F, Govender T, Maguire GEM, Kruger HG, Honarparvar B. The effect of N-methylation of amino acids (Ac-X-OMe) on solubility and conformation: a DFT study. Org Biomol Chem 2015; 13:9993-10006. [DOI: 10.1039/c5ob01565k] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
N-Methylation of amino acid derivatives (Ac-X-OMe, X = Gly, Val, Leu, Ile, Phe, Met, Cys, Ser, Asp and His) leads to an increase in aqueous solubility, lipophilicity and lowering of the cis/trans amide conformational energy barrier (EA).
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Affiliation(s)
- Shah Md. Abdur Rauf
- Catalysis and Peptide Research Unit
- School of Health Sciences
- University of KwaZulu-Natal
- Durban 4001
- South Africa
| | - Per I. Arvidsson
- Catalysis and Peptide Research Unit
- School of Health Sciences
- University of KwaZulu-Natal
- Durban 4001
- South Africa
| | - Fernando Albericio
- Catalysis and Peptide Research Unit
- School of Health Sciences
- University of KwaZulu-Natal
- Durban 4001
- South Africa
| | - Thavendran Govender
- Catalysis and Peptide Research Unit
- School of Health Sciences
- University of KwaZulu-Natal
- Durban 4001
- South Africa
| | - Glenn E. M. Maguire
- Catalysis and Peptide Research Unit
- School of Health Sciences
- University of KwaZulu-Natal
- Durban 4001
- South Africa
| | - Hendrik G. Kruger
- Catalysis and Peptide Research Unit
- School of Health Sciences
- University of KwaZulu-Natal
- Durban 4001
- South Africa
| | - Bahareh Honarparvar
- Catalysis and Peptide Research Unit
- School of Health Sciences
- University of KwaZulu-Natal
- Durban 4001
- South Africa
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Farahani MD, Honarparvar B, Albericio F, Maguire GEM, Govender T, Arvidsson PI, Kruger HG. Proline N-oxides: modulators of the 3D conformation of linear peptides through “NO-turns”. Org Biomol Chem 2014; 12:4479-90. [DOI: 10.1039/c4ob00433g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Honarparvar B, Govender T, Maguire GEM, Soliman MES, Kruger HG. Integrated Approach to Structure-Based Enzymatic Drug Design: Molecular Modeling, Spectroscopy, and Experimental Bioactivity. Chem Rev 2013; 114:493-537. [DOI: 10.1021/cr300314q] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Bahareh Honarparvar
- Catalysis
and Peptide Research Unit and ‡School of Health Sciences, University of KwaZulu Natal, Durban 4001, South Africa
| | - Thavendran Govender
- Catalysis
and Peptide Research Unit and ‡School of Health Sciences, University of KwaZulu Natal, Durban 4001, South Africa
| | - Glenn E. M. Maguire
- Catalysis
and Peptide Research Unit and ‡School of Health Sciences, University of KwaZulu Natal, Durban 4001, South Africa
| | - Mahmoud E. S. Soliman
- Catalysis
and Peptide Research Unit and ‡School of Health Sciences, University of KwaZulu Natal, Durban 4001, South Africa
| | - Hendrik G. Kruger
- Catalysis
and Peptide Research Unit and ‡School of Health Sciences, University of KwaZulu Natal, Durban 4001, South Africa
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Honarparvar B, Kruger HG, Soliman MES, Maguire GEM, Govender T. Molecular modelling studies of synthesized pentacyclo-undecane peptides as potential HIV-1 wild type C-SA protease inhibitors. J Cheminform 2013. [PMCID: PMC3606235 DOI: 10.1186/1758-2946-5-s1-p1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
| | - Hendrik G Kruger
- School of Chemistry, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Mahmoud ES Soliman
- School of Pharmacy and Pharmacology, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Glenn EM Maguire
- School of Chemistry, University of KwaZulu-Natal, Durban 4001, South Africa
| | - Thavendran Govender
- School of Pharmacy and Pharmacology, University of KwaZulu-Natal, Durban 4001, South Africa
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Mousavinezhad Sarasia E, Soliman MES, Honarparvar B. Theoretical study on the molecular electronic properties of salicylic acid derivatives as anti- inflammatory drugs. J STRUCT CHEM+ 2012. [DOI: 10.1134/s0022476612030237] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Makatini MM, Petzold K, Arvidsson PI, Honarparvar B, Govender T, Maguire GEM, Parboosing R, Sayed Y, Soliman MES, Kruger HG. Synthesis, screening and computational investigation of pentacycloundecane-peptoids as potent CSA-HIV PR inhibitors. Eur J Med Chem 2012; 57:459-67. [PMID: 22867528 DOI: 10.1016/j.ejmech.2012.06.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 06/05/2012] [Accepted: 06/09/2012] [Indexed: 10/28/2022]
Abstract
Herein, we present the first pentacycloundecane (PCU) diol peptoid derived HIV protease inhibitors with IC(50) values ranging from 6.5 to 0.075 μM. Five derivatives were synthesized in an attempt to understand the structure activity relationship of this class of compounds for HIV protease inhibition. NMR spectroscopy (new Efficient Adiabatic Symmetrized Rotating Overhauser Effect Spectroscopy, EASY-ROESY) was employed to determine the predominant conformation of the active compound. In this study docking studies and MD simulations provided insight into the binding theme of this class of peptoid inhibitors to the CSA-HIV PR active site. Conserved and stable hydrogen bonding between the hydroxyl groups of the inhibitors and the active site Asp25/Asp25' residues were observed from the docking and along the MD trajectories.
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Affiliation(s)
- Maya M Makatini
- School of Health Sciences, University of KwaZulu Natal, Durban 4001, South Africa
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Honarparvar B, Makatini MM, Pawar SA, Petzold K, Soliman MES, Arvidsson PI, Sayed Y, Govender T, Maguire GEM, Kruger HG. Inside Cover: Pentacycloundecane-diol-Based HIV-1 Protease Inhibitors: Biological Screening, 2 D NMR, and Molecular Simulation Studies (ChemMedChem 6/2012). ChemMedChem 2012. [DOI: 10.1002/cmdc.201290025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Honarparvar B, Makatini MM, Pawar SA, Petzold K, Soliman MES, Arvidsson PI, Sayed Y, Govender T, Maguire GEM, Kruger HG. Pentacycloundecane-diol-Based HIV-1 Protease Inhibitors: Biological Screening, 2D NMR, and Molecular Simulation Studies. ChemMedChem 2012; 7:1009-19. [DOI: 10.1002/cmdc.201100512] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Revised: 03/22/2012] [Indexed: 11/11/2022]
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Makatini MM, Petzold K, Alves CN, Arvidsson PI, Honarparvar B, Govender P, Govender T, Kruger HG, Sayed Y, JerônimoLameira, Maguire GEM, Soliman MES. Synthesis, 2D-NMR and molecular modelling studies of pentacycloundecane lactam-peptides and peptoids as potential HIV-1 wild type C-SA protease inhibitors. J Enzyme Inhib Med Chem 2012; 28:78-88. [PMID: 22339087 DOI: 10.3109/14756366.2011.633907] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In this study, eight non-natural peptides and peptoids incorporating the pentacycloundecane (PCU) lactam were designed and synthesized as potential inhibitors of the wild type C-SA HIV-protease. Five of these inhibitors gave IC(50) values ranging from 0.5 up to 0.75 µM against the resistance-prone wild type C-South African HIV-protease. NMR EASY-ROESY studies enabled us to describe the secondary structure of three of these compounds in solution. The 3D structures of the selected cage peptides were also modelled in solution using QM/MM/MD simulations. Satisfactory agreement between the NMR observations and the low energy calculated structures exists. Only one of these inhibitors (11 peptoid), which showed the best IC(50)(0.5 µM), exhibited a definable 3-D structure in solution. Autodock4 and AutodockVina were used to model the potential interaction between these inhibitors and the HIV-PR. It appears that the docking results are too crude to be correlated with the relative narrow range of experimental IC(50) values (0.5-10 µM). The PCU-peptides and peptoides were several orders less toxic (145 μM for 11 and 102 μM for 11 peptoid) to human MT-4 cells than lopinavir (0.025 μM). This is the first example of a polycyclic cage framework to be employed as an HIV-PR transition state analogue inhibitor and can potentially be utilized for other diseases related proteases. [Figure: see text].
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Sarasia EM, Afsharnezhad S, Honarparvar B, Mollaamin F, Monajjemi M. Theoretical study of solvent effect on NMR shielding tensors of luciferin derivatives. Physics and Chemistry of Liquids 2011. [DOI: 10.1080/00319101003698992] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Makatini MM, Petzold K, Sriharsha SN, Ndlovu N, Soliman ME, Honarparvar B, Parboosing R, Naidoo A, Arvidsson PI, Sayed Y, Govender P, Maguire GE, Kruger HG, Govender T. Synthesis and structural studies of pentacycloundecane-based HIV-1 PR inhibitors: A hybrid 2D NMR and docking/QM/MM/MD approach. Eur J Med Chem 2011; 46:3976-85. [DOI: 10.1016/j.ejmech.2011.05.071] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 05/26/2011] [Accepted: 05/28/2011] [Indexed: 10/18/2022]
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Makatini MM, Petzold K, Sriharsha SN, Soliman MES, Honarparvar B, Arvidsson PI, Sayed Y, Govender P, Maguire GEM, Kruger HG, Govender T. Pentacycloundecane-based inhibitors of wild-type C-South African HIV-protease. Bioorg Med Chem Lett 2011; 21:2274-7. [PMID: 21429747 DOI: 10.1016/j.bmcl.2011.02.105] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Revised: 02/21/2011] [Accepted: 02/24/2011] [Indexed: 11/19/2022]
Abstract
In this study, we present the first account of pentacycloundecane (PCU) peptide based HIV-protease inhibitors. The inhibitor exhibiting the highest activity made use of a natural HIV-protease substrate peptide sequence, that is, attached to the cage (PCU-EAIS). This compound showed nanomolar IC(50) activity against the resistance-prone wild type C-South African HIV-protease (C-SA) catalytic site via a norstatine type functional group of the PCU hydroxy lactam. NMR was employed to determine a logical correlation between the inhibitory concentration (IC(50)) results and the 3D structure of the corresponding inhibitors in solution. NMR investigations indicated that the activity is related to the chirality of the PCU moiety and its ability to induce conformations of the coupled peptide side chain. The results from docking experiments coincided with the experimental observed activities. These findings open up useful applications for this family of cage peptide inhibitors, considering the vast number of alternative disease related proteases that exist.
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Affiliation(s)
- Maya M Makatini
- School of Pharmacy and Pharmacology, University of KwaZulu-Natal, Durban 4001, South Africa
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Irani S, Monajjemi M, Honarparvar B, Atyabi S, Sadeghizadeh M. Investigation of solvent effect and NMR shielding tensors of p53 tumor-suppressor gene in drug design. Int J Nanomedicine 2011; 6:213-8. [PMID: 21499418 PMCID: PMC3075894 DOI: 10.2147/ijn.s14632] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022] Open
Abstract
The p53 tumor-suppressor gene encodes a nuclear phosphoprotein with cancer- inhibiting properties. The most probable cancerous mutations occur as point mutations in exons 5 up to 8 of p53, as a base pair substitution that encompasses CUA and GAT sequences. As DNA drug design represents a direct genetic treatment of cancer, in the research reported computational drug design was carried out to explore, at the Hartree-Fock level, effects of solvents on the thermochemical properties and nuclear magnetic resonance (NMR) shielding tensors of some atoms of CUA involved in the hydrogen-bonding network. The observed NMR shielding variations of the solutes caused by solvent change seemed significant and were attributed to solvent polarity, and solute-solvent and solvent-solute hydrogen-bonding interactions. The results provide a reliable insight into the nature of mutation processes. However, to improve our knowledge of the hydration pattern more rigorous computations of the hydrated complexes are needed.
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Affiliation(s)
- S Irani
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran.
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Monajjemi M, Lee VS, Khaleghian M, Honarparvar B, Mollaamin F. Theoretical Description of Electromagnetic Nonbonded Interactions of Radical, Cationic, and Anionic NH2BHNBHNH2Inside of the B18N18Nanoring. J Phys Chem C 2010. [DOI: 10.1021/jp104274z] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- M. Monajjemi
- Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran, Computational Simulation and Modeling Laboratory (CSML), Department of Chemistry and Center for Innovation in Chemistry, Thailand Center of Excellence in Physics (ThEP), Faculty of Science, Chiang Mai University, Chiang Mai, Thailand, Department of Chemistry, Islamshahr Branch, Islamic Azad University, Islamshahr, Iran, and Department of Chemistry, Qom Branch, Islamic Azad University, Qom, Iran
| | - V. S. Lee
- Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran, Computational Simulation and Modeling Laboratory (CSML), Department of Chemistry and Center for Innovation in Chemistry, Thailand Center of Excellence in Physics (ThEP), Faculty of Science, Chiang Mai University, Chiang Mai, Thailand, Department of Chemistry, Islamshahr Branch, Islamic Azad University, Islamshahr, Iran, and Department of Chemistry, Qom Branch, Islamic Azad University, Qom, Iran
| | - M. Khaleghian
- Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran, Computational Simulation and Modeling Laboratory (CSML), Department of Chemistry and Center for Innovation in Chemistry, Thailand Center of Excellence in Physics (ThEP), Faculty of Science, Chiang Mai University, Chiang Mai, Thailand, Department of Chemistry, Islamshahr Branch, Islamic Azad University, Islamshahr, Iran, and Department of Chemistry, Qom Branch, Islamic Azad University, Qom, Iran
| | - B. Honarparvar
- Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran, Computational Simulation and Modeling Laboratory (CSML), Department of Chemistry and Center for Innovation in Chemistry, Thailand Center of Excellence in Physics (ThEP), Faculty of Science, Chiang Mai University, Chiang Mai, Thailand, Department of Chemistry, Islamshahr Branch, Islamic Azad University, Islamshahr, Iran, and Department of Chemistry, Qom Branch, Islamic Azad University, Qom, Iran
| | - F. Mollaamin
- Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran, Computational Simulation and Modeling Laboratory (CSML), Department of Chemistry and Center for Innovation in Chemistry, Thailand Center of Excellence in Physics (ThEP), Faculty of Science, Chiang Mai University, Chiang Mai, Thailand, Department of Chemistry, Islamshahr Branch, Islamic Azad University, Islamshahr, Iran, and Department of Chemistry, Qom Branch, Islamic Azad University, Qom, Iran
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Monajjemi M, Khosravi M, Honarparvar B, Mollaamin F. Substituent and solvent effects on the structural bioactivity and anticancer characteristic of catechin as a bioactive constituent of green tea. Int J Quantum Chem 2010. [DOI: 10.1002/qua.22612] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Monajjemi M, Mahdavian L, Mollaamin F, Honarparvar B. Thermodynamic Investigation of Enol↔Keto Tautomerism for Alcohol Sensors Based on Carbon Nanotubes as Chemical Sensors. Fullerenes, Nanotubes and Carbon Nanostructures 2010. [DOI: 10.1080/15363830903291564] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Monajjemi M, Razavian MH, Mollaamin F, Naderi F, Honarparvar B. A theoretical thermochemical study of solute-solvent dielectric effects in the displacement of codon-anticodon base pairs. Russ J Phys Chem A 2008. [DOI: 10.1134/s0036024408130207] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Mollaamin F, Baei MT, Monajjemi M, Zhiani R, Honarparvar B. A DFT study of hydrogen chemisorption on V (100) surfaces. Russ J Phys Chem A 2008. [DOI: 10.1134/s0036024408130323] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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