Role of Thioctic Acid in the Transfer of Acyl Groups.

Abstract

When examined in a purified oxidase prepn. from the ciliate Tetrahymena pyriformis, thioctic acid is required for acyl transfer from pyruvate and alpha-ketoglutarate, but not for oxidative activity as measured by reduction of 2,6-dichlorophenolindophenol. The end product of the oxidative phase of pyruvate metabolism is acetate. However, a small amt. of acetaldehyde is formed from pyruvate via a side reaction. It is probably that the product of alpha-ketoglutarate oxidation is succinate and that succinic semialdehyde is formed as a side reaction of this oxidation. Thioctic acid is not required for the acetylation of sulfanilamide from acetyl-Co A.