The formation of dipeptides from amino acids and the 2'(3')-glycyl ester of an adenylate.

The yields of dipeptide obtained from the reaction of 0.2M 2'(3')-O-(glycyl)-adenosine-5'-(O-methylphosphate) and 0.2M amino acid at pH 8.2 ranged from 0.1% to 35.5% for a group of 15 amino acids. The yields of glyser (35.3%), gly-cys (11.8%) and gly-thr (5.4%) were considerably greater than dipeptide yields obtained from any of the other 12 amino acids (less than or equal to 1.7%). Aminolysis of 0.05M 2'(3')-O-(glycyl)-adenosine-5-'-(O-methylphosphate) by 0.4M serine ethyl ester yielded 53% glycylserine diketopiperazine, via N-(glycyl)-serine ethyl ester as a transient intermediate. The prebiotic significance of these reactions is discussed.