CPB, or Carboxypeptidase B1, is a human gene encoded by CPB1. It may also be known as: Carboxypeptidase B; Pancreas-specific protein; PASP; Carboxypeptidase B ; pancreatic carboxypeptidase B; tissue carboxypeptidase B; protaminase; carboxypeptidase B1 (tissue). The encoded protein is an enzyme with an amino acid length of 417 and a mass of 47.4 kDa. Other isoforms may exist. Homologs of this gene exist in other organisms, including: Rat, Frog.