Interaction of M-PMV matrix protein mutants with membranes

Tomáš Kroupa1,2, Michal Doležal1,2, Jan Prchal2, Richard Hrabal2, Tomáš Ruml1

 

1Department of Biochemistry and Microbiology, Institute of Chemical Technology,Technická 5, 166 28 Prague 6, Czech Republic

2Laboratory of NMR Spectroscopy, Institute of Chemical Technology, Technická 5, 166 28 Prague 6, Czech Republic

tomas.kroupa@vscht.cz

 

Mason-Pfizer monkey virus (M-PMV) is a betaretrovirus which is used for studies of the late phase of the retroviral life cycle. Matrix protein is the N-terminal part of the main structural polyprotein Gag of the virus, which is important for the transport of immature viral particles to the plasma membrane and interaction with it. Previously we described structure determination of two double mutants of the matrix protein, i.e., T41I/T78I and Y28F/Y67F that are deficient in budding. In this work we studied the interaction of the wild-type matrix protein and the double mutants with main cellular phospholipids. For NMR measurements water-soluble phospholipids with fatty acid residues with 8 carbons were used instead of insoluble phospholipids with natural fatty acids. Series of NMR experiments were measured in which we observed chemical shift changes in 2D 1H-15N HSQC spectra to define interacting residues of the proteins. For the determination of the equilibrium dissociation constants KD of individual interacting pairs we used chemical shift changes of 31P spectra.