Assembly of the Mitochondrial Membrane System

Abstract

Abstract A fractionation procedure employing bile salts and ammonium sulfate is described for the purification from yeast mitochondria of cytochrome oxidase, coenzyme QH2-cytochrome c reductase, cytochrome b, and a rutamycin-sensitive ATPase. An examination of the properties of these enzymes has shown that their characteristic features are similar to the analogous enzymes isolated from mammalian mitochondria. The purified cytochrome oxidase and the rutamycin-sensitive ATPase are isolated with a low content of phospholipid, and their activity has been found to be stimulated by added phospholipid. The ATPase system of yeast is composed of F1 and a lipoprotein fraction which binds F1 and is necessary for conferral of rutamycin sensitivity.