Organization of Fatty Acid Oxidation in Rat Kidney Mitochondria

Abstract

Long‐chain fatty acids are oxidized by intact rat kidney mitochondria under experimental conditions which permit the location of three long‐chain acyl‐CoA synthesizing systems. Oleate oxidation which is 2,4‐dinitrophenol‐insensitive and which is inhibited by arsenate and excess phosphate, is probably energized by GTP. The isolation of the GTP‐dependent acyl‐CoA synthetase from sonicated kidney mitochondria supports this hypothesis. Oleate oxidation which is insensitive to phosphate and arsenate and requires oligomycin, utilizes “endogenous” ATP and is not linked to added carnitine. The third oleate oxidation system requires added ATP, CoA and phosphate and depends on a carnitine‐linked transport mechanism.