Abstract
The initial step in the infection cycle of human immunodeficiency virus type 1 (HIV-1) involves binding of its surface glycoprotein gpl20 to the T lymphocyte CD4 antigen. CPF-DD is a low molecular weight inhibitor of HIV infectivity that inhibits gpl 20 binding to CD4
in vitro (Finberg et al, Science 249, 287–291, 1990). We find, however, that the actions of CPF-DD are not limited to its ability to interfere with gpl20-CD4 binding; its predominant action is to remove the viral envelope from the underlying core. Subsequently the virions disintegrate. Most enveloped viruses tested were inhibited by CPF-DD, but the infectivity of noneveloped viruses was unaffected or only slightly reduced.