Evidence that the transition of HIV-1 gp41 into a six-helix bundle, not the bundle configuration, induces membrane fusion.

ABSTRACT: Many viral fusion proteins exhibit a six-helix bundle as a core structure. HIV Env-induced fusion was studied to resolve whether membrane merger was due to the transition into the bundle configuration or occurred after bundle formation. Suboptimal temperature was used to arrest fusion at an intermediate stage. When bundle formation was prevented by adding inhibitory peptides at this stage, membranes did not merge upon raising temperature. Inversely, when membrane merger was prevented by incorporating lysophosphatidylcholine (LPC) into cell membranes at the intermediate, the bundle did not form upon optimizing temperature. In the absence of LPC, the six-helix bundle did not form when the temperature of the intermediate was raised for times too short to promote fusion. Kinetic measures showe

SUBMITTER: Melikyan GB 

PROVIDER: S-EPMC2192659 | biostudies-literature | 2000 Oct

REPOSITORIES: biostudies-literature