[The spatial interrelationships between influenza virus hemagglutinin and the lipid phase in the liposomal membrane].

A scheme has been proposed demonstrating the location of tryptophan residues of hemagglutinin molecule in relation to the middle of the lipid layer 1.2 nm thick with a fluorescent probe pyrene. In the immediate proximity to it, one tryptophanyl of protein molecule is located in a hydrophobic "pocket".

[Determination of the accessibility and localization of tryptophan residues in the influenza virus hemagglutinin molecule].

The accessibility and localization of tryptophane residues in the influenza viral hemagglutinin molecule have been determined by measuring specific quenching of tryptophane fluorescence by neutral (acrylamide), anionic (I-) and cationic (Cs+) quenchers. It has been shown that acrylamide quenches 64% of tryptophane fluorescence in H3-hemagglutinin whereas I- and Cs+ quench only 34%. The tryptophanyl residues have been assumed to be located in the hemagglutinin molecule both in the cationic and anionic environments.

[Interaction of isolated influenza virus hemagglutinin with flat lipid membranes].

The interaction of isolated influenza virus hemagglutinin with cell membranes was studied on the model of flat lipid membranes from lecithin and azolectin. Protein molecules were shown to adsorb on the membrane, and permeability of the latter increases when a certain concentration is reached. At the stages of adsorption and penetration into the lipid bilayer the hemagglutinin (HA) showed positive cooperation in interaction with the membranes.