Carboxypeptidase B1, also well known as pancreatic procarboxypeptidase B (PCPB), is a highly pancreas -specific protein (PASP), and has been identified previously as a serum marker for acute pancreatitis and pancreatic graft rejection. As the prototype for those human exopeptidases that cleave off basic C-terminal residues, CPB1 specifically cleaves the C-terminal Arg and Lys residues with a preference for Arg. The B1 and B2 forms of procarboxypeptidase B differ from each other mainly in isoelectric point.The deduced amino acid sequence of PCPB predicts a 416-amino acid preproenzyme consisting of a 15-aa signal peptide, a 95-aa activation peptide and a 307-aa mature chain. The secreted PCPB zymogen is converted to enzymatically active CPB1 by limited proteolysis by trypsin.
Measured by its ability to cleave a colorimetric peptide substrate, Hippuryl-Arg. The specific activity is >5,000 pmoles/min/µg.
Endotoxin:
<1.0 EU per µg of the protein as determined by the LAL method.
Protein Construction:
A DNA sequence encoding the mouse CPB1 (NP_083982.1) precursor (Met 1-Tyr 415) was expressed, with a C-terminal polyhistidine tag.
Purity:
> 94 % as determined by SDS-PAGE
Mol Mass:
47.5 kDa
AP Mol Mass:
43-45 kDa
Formulation:
Lyophilized from sterile 20mM MES, 150mM NaCl, pH 6.5
Shipping:
This product is provided as lyophilized powder which is shipped with ice packs.
Stability and Storage:
Lyophilized proteins are stable for up to 12 months when stored at -20 to -80°C. Reconstituted protein solution can be stored at 4-8°C for 2-7 days. Aliquots of reconstituted samples are stable at < -20°C for 3 months.
