ID 3.4.15.4 DE peptidyl-dipeptidase B. AN atrial di-(tri-)peptidyl carboxylase. AN atriopeptin convertase. AN dipeptidyl carboxyhydrolase. CA Release of a C-terminal dipeptide or exceptionally a tripeptide. CC -!- A membrane-bound, zinc metallopeptidase located in mammalian atrial, CC but not ventricular, myocytes. CC -!- Although it is capable of converting the 126-residue atriopeptin III CC directly to atriopeptin I by releasing a C-terminal tripeptide Phe- CC Arg-Tyr, it is generally restricted to the release of dipeptides. CC -!- In contrast to EC 3.4.15.1 it displays no chlorine dependence and CC shows no action on angiotensin I. CC -!- Conversely, peptidyl-dipeptidase a is unable to release Phe-Arg from CC the C-terminus of atriopeptin II. //