Kirby L C, Klein R A, Coleman J P
Department of Microbiology and Immunology, School of Medicine, East Carolina University, Greensville, North Carolina 27858, USA.
Lipids. 1995 Sep;30(9):863-7. doi: 10.1007/BF02533963.
Conjugated bile acid hydrolase (CBAH) refers to a class of enzymes which catalyze the cleavage of the amino acid moieties from conjugated bile acids. These enzymes are significant because of their role in providing substrates for further microbial metabolism in the gastrointestinal tract. They also are used in research laboratories for the deconjugation of bile acids prior to structural analyses. A continuous spectrophotometric assay for CBAH activity was developed using a conjugate of cholic acid and the chromophore, 5-amino-2-nitro-benzoic acid. The free chromophore is detected by virtue of its absorbance at 410 nm. The CBAH from Clostridium perfringens displayed a Km for this substrate of 120 microM. These results demonstrate that this new compound functions as an effective substrate of the enzyme and forms the basis for a convenient and rapid method to monitor CBAH activity.
共轭胆汁酸水解酶（CBAH）指的是一类能催化从共轭胆汁酸中裂解出氨基酸部分的酶。这些酶很重要，因为它们在为胃肠道中进一步的微生物代谢提供底物方面发挥作用。它们还在研究实验室中用于在进行结构分析之前对胆汁酸进行去共轭。利用胆酸与发色团5-氨基-2-硝基苯甲酸的共轭物开发了一种用于CBAH活性的连续分光光度测定法。通过其在410nm处的吸光度来检测游离发色团。产气荚膜梭菌的CBAH对该底物的Km值为120μM。这些结果表明这种新化合物可作为该酶的有效底物，并构成了一种方便快捷的监测CBAH活性方法的基础。
