Antibody 17b binding at the coreceptor site weakens the kinetics of the interaction of envelope glycoprotein gp120 with CD4

Binding of the antibody epitope 17b to gp120 protein alters V1/V2 loop position thereby blocking the CD4 binding site and weakening CD4 interaction. Data also indicate that the neutralizing effect of the epitope 17b may be due to its blocking of the coreceptor CCR5 binding site on the gp120 protein.