LIPOSOMES AND INFLUENZA-VIRUSES AS AN IN-VITRO MODEL FOR MEMBRANE INTERACTIONS .2. INFLUENCE OF VESICLE SIZE AND PREPARATION METHODS

As previously demonstrated, membrane fusion and transfer of prodrug-ty pe molecules between membranes can be studied with the octadecylrhodam ine B chloride (R18) marker. We use this assay with PR8 influenza viru ses and small (SUV) or large (LW) unilamellar liposomes containing the virus receptor G(D1a) as interacting partners in order to analyse the effect of membrane curvature on fusion and transfer. Computer analysi s revealed no difference in the kinetics of fusion between PR8 with la rge or small liposomes respectively. Lipid transfer, however, is about 5 to 6 times faster from SW than from LUV. We also tested the influen ce of the production method for liposomes, namely detergent dialysis, sonication and extrusion on membrane interactions. Fusion is not affec ted by either, whereas transfer is slower with liposomes produced by s onication.