Immunogen sequence: LQYKVLISNL RNVVEAQFDS RVRATGHSYE KYNKWETIEA WTQQVATENP ALISRSVIGT TFEGRAIYLL KVGKAGQNKP AIFMDCGF. Three different procarboxypeptidases A and two different procarboxypeptidases B have been isolated. The B1 and B2 forms differ from each