STRUCTURAL INVESTIGATION AND KINETIC CHARACTERIZATION OF POTENTIAL CLEAVAGE SITES OF HIV GP160 BY HUMAN FURIN AND PC1

A key event in the biosynthesis of the human immunodeficiency virus is the maturation of the gp160 precursor generating gp120 and gp41, two proteins that are fundamental for the infective process. In vivo, gp16 0 is specifically cleaved at the 515-519 site (REKR down arrow A), in spite of the presence in its sequence of another consensus sequence KA KR down arrow R (residues 507-511). Comparative kinetic studies on syn thetic peptides reproducing different sequences of gp160 by the enzyme s PC1 and furin are reported in this paper. The data demonstrate the h igher efficiency of furin in the cleavage of peptidic substrates with respect to PC1 and its preference for REKR down arrow A vs. KAKR down arrow R. Furthermore, furin and PC1 are unable to process peptides pat terned on the sequence 307-330 of specific viral strains of the gp120 V3 loop. (C) 1995 Academic Press, Inc.