VPX ASSOCIATION WITH MATURE CORE STRUCTURES OF HIV-2

Vpx is a virion-incorporated protein encoded by HIV-2 and certain stra ins of SIV which is necessary for efficient infection of lymphocytes a nd macrophages. To determine the location of Vpx within the HIV-2 part icle, core structures were obtained from mature HIV-2 virions. Analysi s of purified cores reveal the presence of monomeric Vpx as well as a nondenaturable and nonreducible higher order Vpx complex. Characteriza tion of the core-associated Vpx complex suggests it to be a Vpx homodi mer, indicative of high concentrations of Vpx. The incorporation and c oncentration of Vpx in HIV-2 cores support the hypothesis that it func tions within the viral preintegration complex. (C) 1996 Academic Press , Inc.