Logo image
Roles of conserved tryptophans in trimerization of HIV‐1 membrane‐proximal external regions: Implications for virucidal design via alchemical free‐energy molecular simulations
Journal article   Open access   Peer reviewed

Roles of conserved tryptophans in trimerization of HIV‐1 membrane‐proximal external regions: Implications for virucidal design via alchemical free‐energy molecular simulations

Steven T Gossert, Bibek Parajuli, Irwin Chaiken and Cameron F Abrams
Proteins, structure, function, and bioinformatics, v 86(7), pp 707-711
Jul 2018
PMID: 29633345
url
https://doi.org/10.1002/prot.25504View
Published, Version of Record (VoR) Open

Abstract

protein–protein interactions alchemical free‐energy perturbation triple‐helix stability molecular dynamics mutagenesis
The Dual‐Action Virolytic Entry Inhibitors, or “DAVEI's,” are a class of recombinant fusions of a lectin, a linker polypeptide, and a 15‐residue fragment from the membrane‐proximal external region (MPER) of HIV‐1 gp41. DAVEI's trigger rupture of HIV‐1 virions, and the interaction site between DAVEI MPER and HIV‐1 lies in the gp41 component of the envelope glycoprotein Env. Here, we explore the hypothesis that DAVEI MPER engages Env gp41 in a mode structurally similar to a crystallographic MPER trimer. We used alchemical free‐energy perturbation to assess the thermodynamic roles of each of the four conserved tryptophan residues on each protomer of MPER3. We found that a W666A mutation had a large positive ΔΔG for all three protomers, while W672A had a large positive ΔΔG for only two of the three protomers, with the other tryptophans remaining unimportant contributors to MPER3 stability. The protomer for which W672 is not important is unique in the placement of its W666 sidechain between the other two protomers. We show that the unique orientation of this W666 sidechain azimuthally rotates its protomer away from the orientation it would have if the trimer were symmetric, resulting in the diminished interaction of this W672 with the rest of MPER3. Our findings are consistent with our previous experimental study of W‐to‐A mutants of DAVEI. This suggests that DAVEI MPER may engage HIV‐1 Env to form a mixed trimer state in which one DAVEI MPER forms a trimer by displacing a more weakly interacting protomer of the endogenous Env MPER trimer.

Metrics

8 Record Views
4 citations in Scopus

Details

UN Sustainable Development Goals (SDGs)

This publication has contributed to the advancement of the following goals:

#3 Good Health and Well-Being

InCites Highlights

Data related to this publication, from InCites Benchmarking & Analytics tool:

Web of Science research areas
Biochemistry & Molecular Biology
Biophysics
Logo image