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

Journal Article · Mon Jan 09 04:00:00 EST 1984 · Life Sci.; (United States)

DOI:https://doi.org/10.1016/0024-3205(84)90581-2· OSTI ID:6354686

Stack, G; Fricker, L D; Snyder, S H

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 /sup 3/H-labeled substrate and product in chloroform. The substrates /sup 3/H-benzoyl-Phe-Ala-Arg or /sup 3/H-benzoyl-Phe-Leu-Arg are poorly soluble in chloroform due to the charged arginine. The products of carboxypeptidase B-like activity on these substrates, /sup 3/H-benzoyl-Phe-Ala or /sup 3/H-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.

• Research Organization: Johns Hopkins Univ. School of Medicine, Baltimore, MD
• OSTI ID: 6354686
• Journal Information: Life Sci.; (United States), Journal Name: Life Sci.; (United States) Vol. 34:2; ISSN LIFSA
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOCHEMISTRY
BODY
BRAIN
CARBOXYPEPTIDASES
CENTRAL NERVOUS SYSTEM
CHEMISTRY
DRUGS
ENDORPHINS
ENKEPHALINS
ENZYME ACTIVITY
ENZYMES
FLUORESCENCE
FLUORIMETERS
HYDROLASES
LABELLED COMPOUNDS
LUMINESCENCE
MAMMALS
MEASURING INSTRUMENTS
NERVOUS SYSTEM
NEUROREGULATORS
ORGANIC COMPOUNDS
ORGANS
PEPTIDE HYDROLASES
PEPTIDES
POLYPEPTIDES
PROTEINS
RADIOASSAY
RATS
RODENTS
SOLUBILITY
TRITIUM COMPOUNDS
VERTEBRATES