scholarly journals Effects of CD4 Binding on Conformational Dynamics, Molecular Motions, and Thermodynamics of HIV-1 gp120

2019 ◽  
Vol 20 (2) ◽  
pp. 260 ◽  
Author(s):  
Yi Li ◽  
Lei Deng ◽  
Li-Quan Yang ◽  
Peng Sang ◽  
Shu-Qun Liu

Human immunodeficiency virus type-1 (HIV-1) infection is triggered by its envelope (Env) glycoprotein gp120 binding to the host-cell receptor CD4. Although structures of Env/gp120 in the liganded state are known, detailed information about dynamics of the liganded gp120 has remained elusive. Two structural models, the CD4-free gp120 and the gp120-CD4 complex, were subjected to µs-scale multiple-replica molecular dynamics (MD) simulations to probe the effects of CD4 binding on the conformational dynamics, molecular motions, and thermodynamics of gp120. Comparative analyses of MD trajectories in terms of structural deviation and conformational flexibility reveal that CD4 binding effectively suppresses the overall conformational fluctuations of gp120. Despite the largest fluctuation amplitude of the V1/V2 region in both forms of gp120, the presence of CD4 prevents it from approaching the gp120 core. Comparison of the constructed free energy landscapes (FELs) shows that CD4 binding reduces the conformational entropy and conformational diversity while enhancing the stability of gp120. Further comparison of the representative structures extracted from free energy basins/minima of FELs reveals that CD4 binding weakens the reorientation ability of V1/V2 and hence hinders gp120 from transitioning out of the liganded state to the unliganded state. Therefore, locking gp120 conformation via restraining V1/V2 reorientation with small molecules seems to be a promising strategy to control HIV-1 infection. Our computer simulation results support the conformational selection mechanism for CD4 binding to gp120 and facilitate the understanding of HIV-1 immune evasion mechanisms.

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 852
Author(s):  
Ashley Lauren Bennett ◽  
Rory Henderson

The HIV-1 envelope glycoprotein (Env) mediates host cell fusion and is the primary target for HIV-1 vaccine design. The Env undergoes a series of functionally important conformational rearrangements upon engagement of its host cell receptor, CD4. As the sole target for broadly neutralizing antibodies, our understanding of these transitions plays a critical role in vaccine immunogen design. Here, we review available experimental data interrogating the HIV-1 Env conformation and detail computational efforts aimed at delineating the series of conformational changes connecting these rearrangements. These studies have provided a structural mapping of prefusion closed, open, and transition intermediate structures, the allosteric elements controlling rearrangements, and state-to-state transition dynamics. The combination of these investigations and innovations in molecular modeling set the stage for advanced studies examining rearrangements at greater spatial and temporal resolution.


1995 ◽  
Vol 25 (5) ◽  
pp. 1417-1425 ◽  
Author(s):  
Pascale Hubert ◽  
Georges Bismuth ◽  
Marie Körner ◽  
Patrice Debré

2020 ◽  
Author(s):  
Ancy Iruthayaraj ◽  
Sivanandam Magudeeswaran ◽  
Kumaradhas Poomani

<p>Initially, the SARS-CoV-2 virus was emerged from Wuhan, China and rapidly spreading across the world and urges the scientific community to develop antiviral therapeutic agents. Among several strategies, drug repurposing will help to react immediately to overcome COVID-19 pandemic. In the present study, we have chosen two clinical trial drugs TMB607 and TMC310911 are the inhibitors of HIV-1 protease to use as the inhibitors of SARS-CoV-2 main protease (M<sup>pro</sup>) enzyme. To make use of these two inhibitors as the repurposed drugs for COVID-19, it is essential to know the molecular basis of binding mechanism of these two molecules with the SARS-CoV-2 main protease (M<sup>pro</sup>). Understand the binding mechanism; we performed the molecular docking, molecular dynamics (MD) simulations and binding free energy calculations against the SARS-CoV-2 M<sup>pro</sup>. The docking results indicate that both molecules form intermolecular interactions with the active site amino acids of M<sup>pro</sup> enzyme. However, during the MD simulations, TMB607 forms strong interactions with the key amino acids of M<sup>pro</sup> and remains intact. The RMSD and RMSF values of both complexes were stable throughout the MD simulations. The MM-GBSA binding free energy values of both complexes are -43.7 and -34.9 kcal/mol, respectively. This <i>in silico</i> study proves that the TMB607 molecule binds strongly with the SARS-CoV-2 M<sup>pro</sup> enzyme and it is suitable for the drug repurposing of COVID-19 and further drug designing.</p>


Molecules ◽  
2021 ◽  
Vol 26 (1) ◽  
pp. 239
Author(s):  
Shalini Yadav ◽  
Vishnudatt Pandey ◽  
Rakesh Kumar Tiwari ◽  
Rajendra Prasad Ojha ◽  
Kshatresh Dutta Dubey

CD4-mimetic HIV-1 entry inhibitors are small sized molecules which imitate similar conformational flexibility, in gp120, to the CD4 receptor. However, the mechanism of the conformational flexibility instigated by these small sized inhibitors is little known. Likewise, the effect of the antibody on the function of these inhibitors is also less studied. In this study, we present a thorough inspection of the mechanism of the conformational flexibility induced by a CD4-mimetic inhibitor, NBD-557, using Molecular Dynamics Simulations and free energy calculations. Our result shows the functional importance of Asn425 in substrate induced conformational dynamics in gp120. The MD simulations of Asn425Gly mutant provide a less dynamic gp120 in the presence of NBD-557 without incapacitating the binding enthalpy of NBD-557. The MD simulations of complexes with the antibody clearly show the enhanced affinity of NBD-557 due to the presence of the antibody, which is in good agreement with experimental Isothermal Titration Calorimetry results (Biochemistry2006, 45, 10973–10980).


2003 ◽  
Vol 77 (1) ◽  
pp. 713-718 ◽  
Author(s):  
Aarti Raja ◽  
Miro Venturi ◽  
Peter Kwong ◽  
Joseph Sodroski

ABSTRACT The human immunodeficiency virus type 1 (HIV-1) gp120 exterior glycoprotein is conformationally flexible. Upon binding the host cell receptor, CD4, gp120 assumes a conformation that is able to bind the chemokine receptors CCR5 or CXCR4, which act as coreceptors for the virus. CD4-binding-site (CD4BS) antibodies are neutralizing antibodies elicited during natural infection that are directed against gp120 epitopes that overlap the binding site for CD4. Recent studies (S. H. Xiang et al., J. Virol. 76:9888-9899, 2002) suggest that CD4BS antibodies recognize conformations of gp120 distinct from the CD4-bound conformation. This predicts that the binding of CD4BS antibodies will inhibit chemokine receptor binding. Here, we show that Fab fragments and complete immunoglobulin molecules of CD4BS antibodies inhibit CD4-independent gp120 binding to CCR5 and cell-cell fusion mediated by CD4-independent HIV-1 envelope glycoproteins. These results are consistent with a model in which the binding of CD4BS antibodies limits the ability of gp120 to assume a conformation required for coreceptor binding.


2020 ◽  
Vol 23 (1) ◽  
pp. 41-54 ◽  
Author(s):  
Nouman Rasool ◽  
Waqar Hussain

Background: Human Immunodeficiency Virus 1 (HIV-1) is a lentivirus, which causes various HIV-associated infections. The HIV-1 core dissociation is essential for viral cDNA synthesis and phosphorylation of HIV-1 capsid protein (HIV-1 CA) plays an important role in it. Objective: The aim of this study was to explicate the role of three phosphoserine sites i.e. Ser109, Ser149 and Ser178 in the structural stability of HIV-1 CA, and it’s binding with GS-CA1, a novel potent inhibitor. Method: Eight complexes were analyzed and Molecular Dynamics (MD) simulations were performed to observe the stability of HIV-1 CA in the presence and absence of phosphorylation of serine residues at four different temperatures i.e. 300K, 325K, 340K and 350K, along with molecular docking and DFT analysis. Results: The structures showed maximum stability in the presence of phosphorylated serine residue. However, GS-CA1 docked most strongly with the native structure of HIV-1 CA i.e. binding affinity was -8.5 kcal/mol (Ki = 0.579 µM). Conclusion: These results suggest that the phosphorylation of these three serine residues weakens the binding of GS-CA1 with CA and casts derogatory effect on inhibition potential of this inhibitor, but it supports the stability of HIV-1 CA structure that can enhance regulation and replication of HIV-1 in host cells.


iScience ◽  
2020 ◽  
Vol 23 (10) ◽  
pp. 101547
Author(s):  
Jiarong Li ◽  
Jinyan Gu ◽  
Cui Lin ◽  
Jianwei Zhou ◽  
Shengnan Wang ◽  
...  

Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 567
Author(s):  
Zahra Musavizadeh ◽  
Alessandro Grottesi ◽  
Giulia Guarguaglini ◽  
Alessandro Paiardini

The conformational state of the activation loop (A-loop) is pivotal for the activity of most protein kinases. Hence, the characterization of the conformational dynamics of the A-loop is important to increase our understanding of the molecular processes related to diseases and to support the discovery of small molecule kinase inhibitors. Here, we carry out a combination of molecular dynamics (MD) and essential dynamics (ED) analyses to fully map the effects of phosphorylation, ADP, and conformation disrupting (CD) inhibitors (i.e., CD532 and MLN8054) on the dynamics of the A-loop of Aurora-A. MD revealed that the stability of the A-loop in an open conformation is enhanced by single phospho-Thr-288, while paradoxically, the presence of a second phosphorylation at Thr-287 decreases such stability and renders the A-loop more fluctuant in time and space. Moreover, we found that this post-translational modification has a significant effect on the direction of the A-loop motions. ED analysis suggests that the presence of the phosphate moiety induces the dynamics of Aurora-A to sample two distinct energy minima, instead of a single large minimum, as in unphosphorylated Aurora-A states. This observation indicates that the conformational distributions of Aurora-A with both single and double phospho-threonine modifications are remarkably different from the unphosphorylated state. In the closed states, binding of CD532 and MLN8054 inhibitors has the effect of increasing the distance of the N- and C-lobes of the kinase domain of Aurora-A, and the angle analysis between those two lobes during MD simulations showed that the N- and C-lobes are kept more open in presence of CD532, compared to MLN8054. As the A-loop is a common feature of Aurora protein kinases, our studies provide a general description of the conformational dynamics of this structure upon phosphorylation and different ligands binding.


2020 ◽  
Vol 22 (8) ◽  
pp. 4464-4480
Author(s):  
Rui-Ge Wang ◽  
Hong-Xing Zhang ◽  
Qing-Chuan Zheng

MD simulations, MM-PBSA, and SIE analyses were used to investigate the drug resistance mechanisms of two mutations G48T and L89M in HIV-1 protease toward four inhibitors.


Sign in / Sign up

Export Citation Format

Share Document