VIRIP is a natural subfragment of alpha1-antitrypsin (alpha1-AT) and is a broad-based inhibitor of HIV-1. VIRIP was identified from screening a human haemofiltrate derived library and corresponds to residues 353-37 of alpha1-AT, which is the most abundant circulating serine protease inhibitor. VIRIP directly targets the highly conserved viral gp41 fusion peptide to inhibit HIV-1 entry and inhibits a wide variety of HIV-1 strains including variants resistant to protease and reverse transcriptase inhibitors. VIRIP has little or no effect on infection by virions containing HIV-2, SIV, MLV, or VSV env proteins, or by other pathogens such as ebola, herpes simplex or respiratory syncytial virus.
