A New Convenient Assay Tool for Carboxypeptidase A

Carboxypeptidase A (CPA) is an important pancreatic enzyme and has been shown to be a marker of pancreatic disease (1). Carboxypeptidase A is a digestive enzyme that hydrolyzes the carboxyl-terminal peptide bond but works best when the C-terminal residue possesses an aromatic or a bulky aliphatic side chain. CPA can be conveniently assayed using the dipeptide mimetic substrate, acetyl-L-phenylalanyl-L-thiaphenylalanine (2,3). Hydrolysis of this substrate provides the unusual amino acid thiaphenylalanine which rapidly degrades to thiophenol. Utilizing Ellman's reagent to assay free thiol content provides a quantitative analysis of enzyme activity. Leucine aminopeptidase has also been quantified using the dipeptide by Gilvarg and coworkers (3). The substrate is currently available in research quantities; please inquire for bulk amounts.

To view assay scheme click here.

1. Shamamian, P., Marcus, S., Deutsch, E., Maldonado, T., Liu, A., Stewart, J., Eng, K., Gilvarg, C. Presented at the Annual Meeting of the Society for Surgery of the Alimentary Tract, May 1998.
2. Stewart, J.D. and Gilvarg, C. Clin. Chim. Acta, 281/1-2, 19 (1999).
3. Hwang, S. Y., Kingsbury, W. D., Hall, N. M., Jakas, D. R., Dunn, G. L. and Gilvarg, C. Anal. Biochem., 154, 552 (1986).

Peptides International, Inc.
Louisville, Kentucky 40224 USA
Phone: 502-266-8787 or 800-777-4779 (USA only)
Fax: 502-267-1FAX (1329)

HOME |  Back to Products |  E-mail