An Assay of Angiotensin-Converting Enzyme Activity Obtained Using Capillary Electrophoresis

MEI-CHAO CHIANG, SHU-CHUAN YANG, KEN-YUON LI AND TSUN-CHUNG TSAI*

Department of Food Science, Tunghai University, 181, Sec. 3, Taichung Port Rd., Situn District, Taichung City 407, Taiwan, R.O.C.

(Received: October 19, 2004; Accepted: April 27, 2005)

ABSTRACT

   The authors developed a simple method to measure angiotensin-converting enzyme (ACE) activity using capillary electrophoresis (CE). With hippuryl-L-histidyl-L-leucine (HHL) as the substrate, we separated and quantified the enzymatic product, hippuric acid (HA) using capillary zone electrophoresis (CZE). CZE was performed with a 65 cm fused-silica capillary (55 cm effective length, 75 μm I.D.), using a 10 or 20 mM phosphate solution (pH 6.0) as the running buffer with an applied voltage of 20 kV at room temperature.  The HA was identified and monitored at 228 nm.

Key words: angiotensin-converting enzyme, hippuryl-L-histidyl-L-leucine, hippuric acid, capillary electrophoresis