CD4 binding loop responsible for the neutralization of human monoclonal neutralizing antibody Y498

Broad and potent human monoclonal neutralizing antibodies have considerable potential in the prevention and treatment of acquired immunodeficiency syndrome (AIDS). To identify the key amino acid recognition site contacted with neutralizing antibody Y498, peptides were panned from the PhD-12 peptide library and predicted using online software. Then, four key amino acid sites, G367, D368, E370, and V372 located on the CD4 binding loop on gp120 of envelope of human immunodeficiency virus-1 (HIV-1), were found to determine the neutralization of antibody Y498. Residue E370 is in the deep part of the CD4 binding loop, which affects Y498-mediated neutralization. This form of recognition leads to a somewhat limiting neutralization spectrum of neutralizing antibody Y498, although it has some neutralization ability. Further study of the interactions between the neutralizing antibody Y498 and its epitope on the surface of the virus may facilitate vaccine development and so prevent new AIDS cases.