[Changes in cell membrane fluidity evoked by removal of influenza virus receptors with neuraminidase].

The effect of the removal of the influenza virus receptor (N-acetylneuraminic acid) from the erythrocyte membrane by neuraminidase (RDE = receptor destroying enzyme) on the biophysical properties of the cell membrane has been examined using a fluorescent polarization technique. Diphenylhexatriene (DPH) was used as a fluorescent probe for structural ordering in the core of the membrane. A statistically significant decrease in the steady state values of DPH anisotropy was observed in membranes treated with RDE as compared to control. The anisotropy decrease reflected a reduced ordering of the hydrocarbon region of the erythrocyte membrane as well as an increase of its fluidity. An increase of membrane fluidity evoked by the action of influenza virus neuraminidase may play a significant role in the process of influenza virus penetration into the susceptible cell by endocytosis.