[The process of the pH-dependent fusion of the tick-borne encephalitis virus with artificial membranes].

Fusion of TBE virus with liposomes was distinctly determined at pH 7.0 or lower, the maximum degree of fusion being observed at pH 6.4. Disorders in the native structure of TBE virus envelope protein E prevented virus-membrane fusion. Pre-incubation of viral preparations at pH 6.0 completely inhibited the fusion process, while rupture of disulfide bonds in protein E reduced the degree of fusion approximately 2-fold. Reduction of TBE virus infectivity upon changes in the native conformation of protein E as a consequence of disorders in the process of fusion of virions with cell membranes is discussed.