The extracellular processing of HIV-1 envelope glycoprotein gp160 by human plasmin

Abstract

Cleavage of the envelope glycoprotein precursor gp160 of HIV-1 is a prerequisite for the infectivity of HIV-1, and occurs at least in part before gp160 reaches the cell surface. Kexin/subtilisin-related endopeptidases are proposed enzyme candidates for this intracellular processing. In this study, we reveal the possibility that plasminogen binds to the cell surface and part of gp160 escaping intracellular processing is cleaved by plasmin extracellularly. Plasmin cleaves gp160 precisely at the C-terminal arginine residue of gp120, and the processing is effectively inhibited by an analogue peptide of the cleavage motif (RXK/RR) and by plasmin inhibitors.