Improved isolation of rat microsomal cytochrome b5 reductase

Cytochrome b5 reductase (E.C. 1.6.2.2.) has been isolated using a modification of the methods of Takesue and Omura [J. Biochem., 67 (1970) 267], Mihara and Sato [J. Biochem., 71 (1972) 725; and J. Biochem., 78 (1975) 1057]. The methodology involves the isolation of cytochrome b5 reductase from rat liver microsomes using the techniques of lysosomal solubilisation, ammonium sulphate fractionation, gel chromatography and dialysis. This modified method results in a greatly increased yield of enzyme. The purity of the isolated enzyme is shown by disc gel electrophoresis.