Sensitive fluorimetric assay for serum angiotensin-converting enzyme with the natural substrate angiotensin I.


A simple, rapid, highly sensitive and reproducible fluorimetric assay for angiotensin-converting enzyme in untreated serum using the natural substrate based on a similar assay with hippuryl-L-histidine-L-leucine is described. Angiotensin I (0.2 mM in 0.1 M potassium phosphate-30 mM NaCl, pH 7.5; 37 C) is converted to angiotensin II and L-histidyl-L-leucine… (More)