Protein disulphide-isomerase activity in chick-embryo tissues. Correlation with the biosynthesis of procollagen

Protein disulphide-isomerase activity was determined in homogenates of chick-embryo tissues. Activities were highest in tissues active in procollagen synthesis and were maximal at the developmental stage of maximal procollagen synthesis. These variations in protein disulphide-isomerase activity correlate closely with those previously observed for protocollagen hydroxylase activities.