[The spatial interrelationships between influenza virus hemagglutinin and the lipid phase in the liposomal membrane]. / Issledovanie prostranstvennykh vzaimootnoshenii mezhdu gemaggliutinom virusa grippa i lipidnoi fazoi v membrane liposom.

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". At a distance of 2.85 nm from the middle of the lipid zone 3 tryptophanyls are located and the remaining five at a distance over 3.6 nm. After treatment with proteolytic enzyme bromelin of the liposomes with hemagglutinin incorporated into their bilayer, the hydrophobic "anchor" of protein molecule contains one tryptophanyl which is raised by 0.3 nm and its hydrophobic environment is changed.

[Determination of the accessibility and localization of tryptophan residues in the influenza virus hemagglutinin molecule]. / Opredelenie dostupnosti i lokalizatsii ostatkov triptofana v molekule gemaggliutinina virusa grippa.

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. 64% of tryptophanyls have been shown to be located on the surface of the protein globule.

[Interaction of isolated influenza virus hemagglutinin with flat lipid membranes]. / Vzaimodeistvie izolirovannogo gemaggliutinina virusa grippa s ploskimi lipidnymi membranami.

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. At the stage of HA adsorption on the membrane in the presence of M protein, transmembrane interaction occurs between M-protein and HA. It is concluded that molecular mechanisms participate in the HA interaction with cell membrane of the infected host cell.