Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.1 (chymotrypsin)
 10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The potent vasoconstrictor peptide endothelin-1 is proposed to arise via proteolysis of a precursor molecule, "big endothelin," at a unique cleavage site. To aid in the identification of a putative endothelin-converting enzyme, we have developed an assay that mimics the relevant cleavage reaction. The assay takes advantage of the intramolecular fluorescence energy transfer between the scissile-site tryptophan and a dansyl moiety present in the same synthetic substrate. Cleavage of the peptide chain separates the fluorophore and quencher, resulting in an increase in fluorescence. The assay has been validated using chymotrypsin as a model protease and has been employed in the identification of novel endothelin-converting enzyme activities.
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PMID:A fluorogenic assay for endothelin-converting enzyme. 180 35

The conversion of big endothelin to endothelin by alpha-chymotrypsin was determined by following its single Trp fluorescence polarization. This provides a novel, simple, fast, and sensitive identifying assay in the search for a native endothelin-converting enzyme.
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PMID:Fluorescence polarization assay for endothelin-converting enzymes. 747 23

A simple, solid-phase assay usable for the detection of endothelin-converting enzyme activity and inhibitors has been developed. It uses a multimeric peptide immobilized on microtiter plates that is able to specifically recognize the Big Endothelin fragment 16-32 derivatized with biotin. This fragment is cleaved between residues 21-22 by alpha-chymotrypsin with almost the same proteolysis rate as Big Endothelin, and after enzyme treatment it does not bind to the multimeric peptide adsorbed on the microtiter plates. The amount of uncleaved peptide bound to the plate is detected by subsequent treatment with streptavidin conjugated to peroxidase, followed by a chromogenic reaction. Model inhibitor profiles generated for alpha-chymotrypsin, a protease known to convert Big Endothelin in endothelin, demonstrated the utility of this assay as a rapid high-throughput aid in the study of Big Endothelin enzymatic processing and possibly in the identification of putative enzyme inhibitors.
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PMID:Peptide-based assay for the identification of endothelin-converting enzyme inhibitors. 848 40