Lytic Inactivation of Human Immunodeficiency Virus by Dual Engagement of gp120 and gp41 Domains in the Virus Env Protein Trimer

We recently reported the discovery of a recombinant chimera, denoted DAVEI (dual-acting virucidal entry inhibitor), which is able to selectively cause specific and potent lytic inactivation of both pseudotyped and fully infectious human immunodeficiency virus (HIV-1) virions. The chimera is composed of the lectin cyanovirin-N (CVN) fused to the 20-residue membrane-proximal external region (MPER) of HIV-1 gp41. Because the Env gp120-binding CVN domain on its own is not lytic, we sought here to determine how the MPER(DAVEI) domain is able to endow the chimera with virolytic activity. We used a protein engineering strategy to identify molecular determinants of MPER(DAVEI) that are important for function. Recombinant mutagenesis and truncation demonstrated that the MPER(DAVEI) domain could be significantly minimized without loss of function. The dependence of lysis on specific MPER sequences of DAVEI, determination of minimal linker length, and competition by a simplified MPER surrogate peptide suggested that...