title: A fluorescence-based protocol for quantifying angiotensin-converting enzyme activity.
abstract: The determination of angiotensin-converting enzyme (ACE) activity represents a useful tool in the study of different health pathologies, such as hypertension. This protocol describes a fluorescent assay for measuring ACE activity in vitro with high precision and sensitivity. The method relies on the ability of ACE to hydrolyse the internally quenched fluorescent substrate o-aminobenzoylglycyl-p-nitro-L-phenylalanyl-L-proline. The generation of the fluorescent product o-aminobenzoylglycine can be continuously monitored, preferably using a microtiter-plate fluorometer, though the use of a conventional cuvette fluorometer would also be possible. The method has important advantages with respect to other assays, because it involves only a one-step reagent, is easy to carry out and allows the analysis of an elevated number of samples in shorter times. It can be completed in one and a half hours. In addition, the fact that all reagents are commercially available allows the rapid introduction of the assay into the laboratory.
authors.affiliation: Instituto de Agroquímica y Tecnología de Alimentos (CSIC), P.O. Box 73, 46100 Burjassot (Valencia), Spain. ciesen@iata.csic.es
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Sentandreu
authors.forename: Fidel
authors.initials: F
authors.lastname: Toldrá
mesh_terms: D000618:Aminohippuric Acids / Q000032:analysis; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000032:analysis; D000818:Animals; D005470:Fluorometry / Q000379:methods*; D020128:Inhibitory Concentration 50; D009842:Oligopeptides / Q000378:metabolism; D007703:Peptidyl-Dipeptidase A / Q000032:analysis* / Q000378:metabolism; D011817:Rabbits
chemical_list: D000618:Aminohippuric Acids; D000806:Angiotensin-Converting Enzyme Inhibitors; D009842:Oligopeptides; C033412:2-aminohippuric acid; C043712:2-aminobenzoylglycyl-4-nitrophenylalanyl-proline; D007703:Peptidyl-Dipeptidase A