| Abstract: | SYNOPSIS. Chilomonas paramecium contains 2 different fatty acid activating enzymes (FAAE), one of which utilizes acetate as a substrate, while the other catalyzes the reaction with either butyrate or hexanoate. The site of greatest activity of these enzymes was found to be not in the mitochondrion, but in the “soluble” portion of the cell. Synthesis of acetyl FAAE is constitutive; this enzyme is present regardless of the substrate in the growth medium. The synthesis of the butyryl-hexanoyl FAAE is induced by the presence of either of the substrates. The details of induction of the butyryl enzyme in acetate-grown cells, and the de-adaptation of cells grown in butyrate and transferred to acetate, are given. One mole of pyrophosphate is produced for each mole of CoA-SH reacting, (thus establishing the prevalence of the acyl-adenylate pathway in Chilomonas fatty acid activation. |
