INCORPORATION OF AMINO ACIDS INTO CHICK PROTEINS DURING EMBRYONIC GROWTH

Abstract

Radioactive glycine and methionine were injected into the yolk of 4-day-old embryonated eggs. There was a rapid increase in total incorporated radioactivity with both amino acids. The specific activity of the protein increased until the seventh day, after which time there was a sharp decrease. Radioactivity from DL-methionine-S35was incorporated in larger amounts than from glycine-2-C14. An increase in the proteolytic activity of the yolk with age was demonstrated.