A sensitive radiochemical assay for angiotensin-converting enzyme (kinase II)

Sensitive colorimetric assay for angiotensin converting enzyme in serum.

A sensitive colorimetric procedure has been developed for the assay of angiotensin converting enzyme (EC 3.4.15.1) in serum. Serum (10 microL) is incubated for 30 min with hippuryl-glycyl-glycine as described earlier (Clin Chem 28: 1352-1355, 1982). After a Folin-Wu deproteinization, the liberated glycyl-glycine is derivatized with a borate-buffered (pH 9.3) trinitrobenzenesulfonate solution (6...

Angiotensin Converting Enzyme in Sarcoidosis

Inhibitor binding assay for angiotensin-converting enzyme.

We describe a new principle for the determination of enzymes, here applied to angiotensin-converting enzyme (ACE, EC 3.4.15.1) in human serum. The enzyme inhibitor binding assay is based on specific binding of labeled inhibitor to the active center of the enzyme. Serum (10-15 microL) is incubated with 125I-labeled ACE inhibitor (" 351A ," a p- hydroxybenzamidine derivative of N-(1-carboxy-3-phe...

Characterization of a spectrophotometric assay for angiotensin converting enzyme.

Although serum angiotensin converting enzyme (EC 3.4.15.1) activity has generally been shown to be increased in patients with sarcoidosis, considerable variation in the diagnostic usefulness of this test has been reported. We investigated the possibility that this variation may be the result of inhibition of the widely used spectrophotometric assay by various substances. We also prospectively e...

Direct spectrophotometric assay for angiotensin-converting enzyme in serum.

The appropriate conditions for determining angiotensin-converting enzyme in human serum with use of 2-furanacryloyl-L-phenylalanylglycylglycine as substrate are described. The method, a modification of that reported by Holmquist et al. (Anal. Biochem. 95:540-548, 1979) for purified rabbit lung enzyme, is based on the blue shift of the absorption spectrum that occurs upon hydrolysis of the subst...