Abstract
The effects of the protein and amino acid composition in the diet on the biosynthesis of protein-bound lipoic acid, which is considered to be the active form of lipoic acid for oxidative decarboxylation of α-keto acids, such as pyruvic acid and α-ketoglutaric acid, were observed and the following findings were observed.
1. Decreased incorporation of lipoic acid into the total mitochondrial protein of the liver was revealed in the low protein group.
2. The incorporation of the acid per mg nitrogen of liver mitochondria of the low protein group was unexpectedly higher than that in the standard diet group.
3. In the lysine-, tryptophan- or threonine-deficient group, the incorporation of lipoic acid into the mitochondrial proteins was decreased, but in the methionineor phenylalanine-deficient group, almost the same incorporation was observed as the standard diet group.
