APOLIPOPROTEIN-A-I INTERACTS WITH THE N-TERMINAL FUSOGENIC DOMAINS OF SIV (SIMIAN IMMUNODEFICIENCY VIRUS) GP32 AND HIV (HUMAN-IMMUNODEFICIENCY-VIRUS) GP41 - IMPLICATIONS IN VIRAL ENTRY

Previous studies showed that apoAl, the major protein component of HDL (High Density Lipoprotein), inhibited HIV infectivity and virus-induced syncytia formation. The mechanism of inhibition is unknown. We bring here evidence that the amphipathic helices of apoAl interact with the N-terminal peptides of SIV gp32 and HIV gp41. These peptides have been shown to be associated with the initial steps of the fusion between the host cell and the virus. Binding of apoAl to these peptides prevents the insertion of the fusogenic domains into the cell membrane and inhibits the fusion and the entry of the virus into the host cell. © 1992 Academic Press, Inc.