Conjugated Amino Acids in the Non-Cationic Fraction of Pea Seedlings

Many amino acids were liberated by acid hydrolysis of the non-cationic fraction of pea seedling extract, suggesting the existence of ninhydrin-negative conjugated amino acids. The non-cationic fraction was subjected to cellulose column chromatography and gel-filtration with Sephadex G-15 and was separated into 20 fractions which gave ninhydrin color after alkaline hydrolysis. Alanine and glutamic acid, the most predominant amino acids in the hydrolyzate of the non-cationic fraction, occurred in many fractions. These results indicated that alanine and glutamic acid existed in various conjugated forms. In one of the fractions, there was evidence suggesting the presence of a peptide containing equimolar amounts of alanine and glutamic acid.