Exploring converse molecular mechanisms of anti-HIV-1 antibodies using a synthetic CXCR4 mimic

Different molecular mechanisms of the two broadly neutralizing anti-HIV-1 antibodies b12 and VRC01, as evidenced by their converse effects on the interaction of HIV-1 envelope glycoprotein gp120 with cellular coreceptors, were demonstrated using a synthetic CXCR4 mimetic peptide (CX4-M1) as coreceptor surrogate. While the interaction of gp120 with CX4-M1 was distinctly enhanced by VRC01, b12 was shown to have the contrary effect, and also to inhibit the VRC01-induced enhancement of gp120 binding to the CXCR4 mimetic peptide.