Interactions with human CD4 protein leads to helix-to-coil transition in HIV-gp120 aiding CCR5 attachment and viral entry: An in silico structural biology approach for AIDS

Abstract

Human immuno-deficiency virus (HIV) is assisted by its glycoprotein; gp120 for its human host cell invasion via fusion to cause AIDS. Documentation documents a structural change in gp120, after its first interaction with human CD4 protein which further attracts CCR5 protein, thereby paving its way for viral entry. So, gp120 was homology modeled efficiently. Trio docking analysis led to the disclosure of the responsible residues from protein complexes. Polar-charged residues from CD4 protein played a pivotal role. The trio complex was optimized and simulated. Conformational switches and other stability parameters for gp120 was computed, compared, and analyzed at three different stages; before any interaction and after CD4 and CCR5 interaction separately. They were statistically significant with an overall helix-to-coil transition.