Vantrappen G, Ghoos A Y, Peeters T
Am J Dig Dis. 1976 Jul;21(7):547-52. doi: 10.1007/BF01464761.
The effect of bile acids on the bacteriolytic activity of lysozyme towards Micrococcus lysodeikticus was studied in vitro. All bile acids tested inhibited lysozyme activity. Conjugated bile acids were better inhibitors than their unconjugated homologs and sulfation resulted in still stronger inhibition. A study of UV-difference spectra of bile acid-lysozyme mixtures suggests that bile acids distort the tertiary structure of the enzyme. The inhibition-concentration curves of micelle-forming bile acids were bell-shaped, and peak inhibition was apparently related to the critical micellar concentration. The inhibition-concentration curves of sulfated bile acids, which do not form micelles, are characterized by a plateau of maximal inhibition. A mechanism of lysozyme activation by bile acid micelles is proposed. Our results illustrate the complex interactions between antibacterial compounds in the gut. As bile acids are known to inhibit lipase activity as well, these studies suggest that bile acids may have an important influence on intestinal enzyme activity in general.
在体外研究了胆汁酸对溶菌酶针对溶壁微球菌的溶菌活性的影响。所有测试的胆汁酸均抑制溶菌酶活性。结合型胆汁酸比其未结合的同系物是更好的抑制剂，而硫酸化导致更强的抑制作用。对胆汁酸 - 溶菌酶混合物的紫外差光谱研究表明，胆汁酸会扭曲酶的三级结构。形成胶束的胆汁酸的抑制浓度曲线呈钟形，最大抑制作用显然与临界胶束浓度有关。不形成胶束的硫酸化胆汁酸的抑制浓度曲线的特征是最大抑制作用的平稳期。提出了胆汁酸胶束激活溶菌酶的机制。我们的结果说明了肠道中抗菌化合物之间的复杂相互作用。由于已知胆汁酸也会抑制脂肪酶活性，这些研究表明胆汁酸可能总体上对肠道酶活性有重要影响。
