A sensitive radiometric assay for enkephalin convertase and other carboxypeptidase B-like enzymes

Gary Stack, Lloyd D. Fricker, Solomon H. Snyder

Research output: Contribution to journalArticle


A sensitive radiometric assay for carboxypeptidase B-like enzymes has been developed using enkephalin convertase, an enkephalin synthesizing carboxypeptidase. The assay is based on the differential solubility of 3H-labeled substrate and product in chloroform. The substrates 3H-benzoyl-Phe-Ala-Arg or 3H-benzoyl-Phe-Leu-Arg are poorly soluble in chloroform due to the charged arginine. The products of carboxypeptidase B-like activity on these substrates, 3H-benzoyl-Phe-Ala or 3H-benzoyl Phe-Leu partition quantitatively into chloroform, allowing rapid separation of product from substrate. This assay is approximately 100 times more sensitive than a similar fluorometric assay utilizing dansyl-Phe-Ala-Arg as a substrate.

Original languageEnglish (US)
Pages (from-to)113-121
Number of pages9
JournalLife Sciences
Issue number2
StatePublished - Jan 9 1984


ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Pharmacology, Toxicology and Pharmaceutics(all)

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