Cloning, sequencing and expression of the gene encoding a major allotypic preprocarboxypeptidase A from bovine pancreas.

A cDNA encoding one of two major allotypic forms of bovine pancreatic preprocarboxypeptidase A (preproCPA) has been cloned, and its entire nucleotide (nt) sequence determined. The cloned cDNA contains a 26-nt 5'-noncoding region, a 1260-nt open reading frame and a 51-nt 3'-noncoding region. The amino acid (aa) sequence deduced from the gene sequence contains Ile179, Ala228 and Val305 at allotypic aa residues. The procarboxypeptidase A (proCPA) was produced in yeast and secreted into the medium. Upon treatment with trypsin, proCPA generated an active enzyme with the same size as the mature carboxypeptidase A (CPA), as analyzed by use of anti-CPA polyclonal antibody.