Abstract
In this report, the properties of water soluble protein extracted from gastrocnemius muscle and liver of rats fed on protein-free and threonine deficien t diets were investigated.
No significant differences in the amino acid composition were detected among the extracts from the rats fed on protein-free, threonine deficient and normal diets. The extracts from gastrocnemius muscle and liver were dialyzed against phosphate buffer at pH 5.0 and fractionated by chromatography on cellulose phosphate by stepwise elution with buffers ranging from pH 5.0 to 10.0.
From the effluent diagrams of water soluble protein of the muscle, no significant difference was recognized among the rats fed on above-mentioned diets. But the increase of protein fraction coming through with the buffer at pH 5.0 and the decrease of the fraction at pH 7.0 were recognized from the effluent diagrams of water soluble protein of the liver extracted from the rats fed on protein-free and threonine deficient diets.
Tryptophan content and aldolase activity of the fractionated protein were also assayed. No significant difference in the tryptophan content was recognized among the muscle extracts from the rats fed on different diets, but a slight decrease was found in the liver extracts from the rats fed on deficient diets. Aldolase activity of the muscle and liver protein of the rats fed on protein-free diet was slightly lower than that of the rats fed on normal diet, but no difference was observed between the rats fed on threonine deficient and normal diets.
No significant difference in the amino acid composition of the proteins eluted with the phosphate buffer at pH 7.0 was recognized between the rats fed on threonine deficient and normal diets.
