Kinetic study of angiotensin converting enzyme activity by capillary electrophoresis after in-line reaction at the capillary inlet.
The in-capillary reaction of angiotensin converting enzyme (ACE) with the tripeptide substrate hippuryl-L-histidyl-L-leucine was studied. ACE activity was determined by the quantitation of the product, hippuric acid, at 230 nm. Reaction occurred at the capillary inlet during a predetermined waiting period, followed by the electrophoretic separation of the compounds. When the set-up was reversed, i.e. reaction at the opposite side after short-end injection of enzyme and substrate, separation was achieved in less than 5 min. Using the Lineweaver-Burk equation, an average Michaelis constant for ACE from rabbit lung was calculated to be 1.16 +/- 0.12 mM, a value consistent with previously reported data.
Van Dyck
Sigrid
S
Laboratorium voor Farmaceutische Chemie en Analyse van Geneesmiddelen, Katholieke Universiteit Leuven, Van Evenstraat 4, B-3000 Leuven, Belgium.
Vissers
Stijn
S
Van Schepdael
Ann
A
Hoogmartens
Jos
J
D002138:Calibration; D019075:Electrophoresis, Capillary / Q000379:methods*; D007700:Kinetics; D009842:Oligopeptides / Q000378:metabolism; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism*
D009842:Oligopeptides; C010980:hippuryl-histidyl-leucine; D007703:Peptidyl-Dipeptidase A