The research goals are directed towards an understanding of mechanisms of membrane fusion mediated by viral spike glycoproteins. We are specifically studying the mode of action of the G protein of Vesicular Stomatitis Virus (VSV) and the HN and F proteins of Sendai Virus. Specific topics include: i) development of fluorescent methods to study kinetics and extent of adhesion and fusion using intact and reconstituted virions, and liposomes and cells as targets; ii) development of methods to analyze reconstitution of viral spike glycoproteins; iii) analysis of factors which determine approach of virus to target (electrostatics, steric constraints); iv) analysis of factors which promote membrane deformation and destabilization (liposome size, lipid composition, osmotic forces); v) Examination of possible effects of pH-gradient or membrane potential on fusion rates; vi) analysis of the role of cooperativity of viral glycoproteins in mediating fusion; vii) Examination of the disposition of the fusion protein after the fusion event; viii) Identification of possible fusion intermediates; ix) Development of methods to study fusion activity of mutants of viral proteins using cloned viral membrane protein sequences expressed in transfected cells; x) Structural studies of viral proteins; xi) Development of methods for using reconstituted viral envelopes as vehicles for specific delivery of materials into cells.
