Assays for Angiotensin Converting Enzyme Inhibitory Activity

✍ Scribed by Bin-Wha Chang; Richie L.C. Chen; I-Jen Huang; Hsien-Chang Chang

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 66 KB
• Volume: 291
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1006/abio.2001.5005

✦ Synopsis

A colorimetric method and a capillary electrophoresis procedure were developed for quantifying histidyl-leucine and hippurate, respectively. The colorimetric method is sensitive (extinction coefficient = 7.5 mM(-1) cm(-1)) and reproducible (CV = 1.7%, n = 5), which is based on a selective chromogenic reaction for histidyl-leucine (lambda(max) = 390 nm) using o-phthalaldehyde. For samples containing unusually high levels of histidine and/or histidyl peptides, the separation-based approach is preferable. The capillary electrophoresis method makes use of an in-capillary microextraction technique; complicated samples can be measured in less than 4 min without pretreatment. Protocols using both methods to measure angiotensin converting enzyme inhibitory activity were proposed.