HIV Research Today is a free monthly online journal that collates and summarizes the latest research about HIV, including details on human immunodeficiency virus, testing, treatment, prevention, vaccines, aids.

Cooperative effects in phospholipid monolayers induced by a peptide from HIV-1 capsid protein.

Moraes ML, Bonardi C, Mendonça CR, Campana PT, Lottersberger J, Tonarelli G, Oliveira ON, Beltramini LM

Instituto de Física de São Carlos, USP, CP 369, 13560-970 São Carlos, Brazil.

The study of interactions between biological molecules and model membranes is essential for the understanding of a number of physiological mechanisms involved in viral infections and dissemination. In this paper, the analysis of the interaction between a peptide from the p24 protein of Human Immunodeficiency Virus type 1 (HIV-1) and a phospholipid monolayer has pointed to a cooperative response in which very small amounts of peptide p24-1 (e.g. 0.05 mol%) can lead to measurable effects. Monolayer surface pressure and surface potential isotherms were affected for peptide concentrations as low as 0.05 mol%, with saturation at 0.5 mol%. The expansion effect from p24-1 is confirmed by changes in morphology of the monolayers using Brewster angle microscopy. Even though p24-1 is disordered in aqueous solutions, the interaction with dipalmitoyl phosphatidylcholine (DPPC) causes it to adopt an alpha-helix structure, as shown by circular dichroism (CD) data for multilamellar vesicles (MLV). The expansion of the phospholipid monolayer in a cooperative way may imply that p24-1 has potential antiviral activity, by participating in the cell rupture, with no need of specific receptors in the membrane.

Published 8 February 2005 in Colloids Surf B Biointerfaces, 41(1): 15-20.
Full-text of this article is available online (may require subscription).

© 2004-2008 HIV Research Today. All Rights Reserved.