Modification of the furanacryloyl-L-phenylalanylglycylglycine assay for determination of angiotensin-I-converting enzyme inhibitory activity

B. A. Murray, D. J. Walsh, R. J. FitzGerald

Research output: Contribution to journalArticlepeer-review

Abstract

Angiotensin-I-converting enzyme (ACE, EC 3.4.15.1) plays a central role in the regulation of blood pressure in man. The objective of this study was to evaluate and modify the furanacryloyl-L-phenylalanylglycylglycine (FAPGG) assay method for quantification of ACE activity. The fixed time conditions developed for assay of ACE activity were as follows: 0.8 mM FAPGG, 175±10 units l-1 ACE, incubation at 37°C for 30 min and enzyme inactivation with 100 mM ethylenediaminetetra-acetic acid (EDTA). Hydrolysis of FAPGG to FAP and GG was quantified by measuring the decrease in absorbance at 340 nm. It was shown that increasing the level ACE activity in the assay from 155 to 221±15 units l-1 resulted in a corresponding increase in the apparent IC50 value for Captopril® from 9.10 to 39.40 nM. Similar trends in the apparent IC50 values for a whey protein hydrolysate were obtained. The results demonstrate the requirement for carefully controlling ACE activity levels in the assay in order to obtained comparable and reproducible values for the inhibitory potency of ACE inhibitors.

Original languageEnglish
Pages (from-to)127-137
Number of pages11
JournalJournal of Biochemical and Biophysical Methods
Volume59
Issue number2
DOIs
Publication statusPublished - 31 May 2004

Keywords

  • ACE inhibition
  • Angiotensin-I-converting enzyme
  • Captopril
  • FAPGG
  • Functional food ingredients
  • IC
  • Whey protein

Fingerprint

Dive into the research topics of 'Modification of the furanacryloyl-L-phenylalanylglycylglycine assay for determination of angiotensin-I-converting enzyme inhibitory activity'. Together they form a unique fingerprint.

Cite this