A specific detection method for multiple forms of cystine aminopeptidase (oxytocinase-isoenzymes) after polyacrylamide gel electrophoresis.

A simple and specific detection method for multiple forms of cystine aminopeptidase (oxytocinase-isoenzymes) in pregnancy serum is described using S-benzyl-L-nitroanilide as substrate. The relative distribution of both cystine aminopeptidase isoenzymes at different stages of pregnancy is given.