Recombinant Carboxypeptidase B (CPB) is derived from rat pancreas and recombinantly expressed in Escherichia coli. With a molecular weight of approximately 33.8 kDa, it exhibits enzymatic properties identical to those of animal-derived carboxypeptidase B, yet contains no animal-derived components and is free from animal-derived viral contamination. It can serve as a replacement for animal-derived carboxypeptidase B in various biotechnological processes.

Carboxypeptidase B is a widely used Zn²⁺ metalloprotease, traditionally isolated from the pancreas of various animals. It specifically catalyzes the hydrolysis of basic amino acids, such as L-arginine and L-lysine, from the C-terminus of peptides and proteins. The activity of carboxypeptidase B is competitively inhibited by arginine and lysine, and its enzymatic activity is also suppressed by metal ion chelators such as EDTA.