Fusion activity of HIV gp41 fusion domain is related to its secondary structure and depth of membrane insertion in a cholesterol-dependent fashion.

ABSTRACT: The human immunodeficiency virus (HIV) gp41 fusion domain plays a critical role in membrane fusion during viral entry. A thorough understanding of the relationship between the structure and the activity of the fusion domain in different lipid environments helps to formulate mechanistic models on how it might function in mediating membrane fusion. The secondary structure of the fusion domain in small liposomes composed of different lipid mixtures was investigated by circular dichroism spectroscopy.  The fusion domain formed an α-helix in membranes containing less than 30 mol% cholesterol and  formed β-sheet secondary structure in membranes containing ≥30 mol% cholesterol. EPR spectra of spin-labeled fusion domains also indicated different conformations in membranes with and without choleste

SUBMITTER: Lai AL 

PROVIDER: S-EPMC3654243 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature