- alpha Arg-237 in Methylophilus methylotrophus (sp. W3A1) electron-transferring flavoprotein affords approximately 200-millivolt stabilization of the FAD anionic semiquinone and a kinetic block on full reduction to the dihydroquinone. Talfournier, F., Munro, A.W., Basran, J., Sutcliffe, M.J., Daff, S., Chapman, S.K., Scrutton, N.S. J. Biol. Chem. (2001)