The influence of N-linked glycans on the molecular dynamics of the HIV-1 gp120 V3 loop.

N-linked glycans attached to specific amino acids of the gp120 envelope trimer of a HIV virion can modulate the binding affinity of gp120 to CD4, influence coreceptor tropism, and play an important role in neutralising antibody responses. Because of the challenges associated with crystallising fully glycosylated proteins, most structural investigations have focused on describing the features of a non-glycosylated HIV-1 gp120 protein. Here, we use a computational approach to determine the influence of N-linked glycans on the dynamics of the HIV-1 gp120 protein and, in particular, the V3 loop.

Defining the structural origin of the substrate sequence independence of O-GlcNAcase using a combination of molecular docking and dynamics simulation.

Protein glycosylation with O-linked N-acetylglucosamine (O-GlcNAc) is a post-translational modification of serine/threonine residues in nucleocytoplasmic proteins. O-GlcNAc has been shown to play a role in many different cellular processes and O-GlcNAcylation is often found at sites that are also known to be phosphorylated. Unlike phosphorylation, O-GlcNAc levels are regulated by only two enzymes, O-GlcNAc transferase (OGT) and O-GlcNAc hydrolase (O-GlcNAcase or OGA).