Molecular dynamics simulation on the complexes of N-terminal region of HIV-1 gp41 and its C-peptide inhibitors

Computer-Aided Approaches for Targeting HIVgp41

Virus-cell fusion is the primary means by which the human immunodeficiency virus-1 (HIV) delivers its genetic material into the human T-cell host. Fusion is mediated in large part by the viral glycoprotein 41 (gp41) which advances through four distinct conformational states: (i) native, (ii) pre-hairpin intermediate, (iii) fusion active (fusogenic), and (iv) post-fusion. The pre-hairpin intermediate is a particularly attractive step for therapeutic intervention given that gp41 N-terminal heptad repeat (NHR) and C-terminal heptad repeat (CHR) domains are transiently exposed prior to the formation of a six-helix bundle required for fusion. Most peptide-based inhibitors, including the FDA-approved drug T20, target the intermediate and there are significant efforts to develop small molecule alternatives. Here, we review current approaches to studying interactions of inhibitors with gp41 with an emphasis on atomic-level computer modeling methods including molecular dynamics, free energy analysis, and docking. Atomistic modeling yields a unique level of structural and energetic detail, complementary to experimental approaches, which will be important for the design of improved next generation anti-HIV drugs.

Prediction of the binding model of HIV-1 gp41 with small molecule inhibitors

Despite the synthetic peptides inhibit HIV-1 entry; its application of this peptide therapy may be limited due to the high cost of the peptide production and lack of its oral availability. Thus, it is necessary to identify the small molecule inhibitors reacting with the same or overlapping target sites on gp41 recognizing the antiviral peptides. In this work, a small inhibitor (TP1) is docked into the hydrophobic grooves of gp41 by using AutoDock software, resulting in five alternative energetically favorable models. The data from other studies were used to define our preferred models. We found that only one binding mode is supported by the experimental evidence. The model could be used to design more effective HIV-1 inhibitors targeted to the HIV-1 gp41 core structure.