SPECTROSCOPIC STUDIES OF MODEL DIGESTIVE SYSTEMS

胆汁分泌的膜脂和肠 酰基甘油的消化是由生理洗涤剂介导的 --包括胆汁盐、脂肪酸、甘油单酯，以及 磷脂 每一组事件都依赖于 分子聚集体，以便有效的运输和酶促 可以完成水解。 为了制定详细的 这些过程的分子理解，建议 进行一系列的光谱研究， 模型消化混合物结构信息及其 在胃肠道中起作用。 模型胆汁混合物的动态结构将是 二维核磁共振（NMR）研究 松弛实验：脂-脂排列，分子 流动性和双层有序将被评估和相关， 酶辅助 在脂质混合物中达特 甘油酯消化阶段，准弹性光散射和 将采用13 C NMR测量来描绘大小， 表面特征使得这些基材如此容易受到 由脂肪酶-辅脂酶系统攻击。 最后，注意力将 明确地集中在辅脂酶的构象及其 复合物与胆汁盐洗涤剂，使用电池的2D NMR 技术.

Both the biliary secretion of membrane lipids and the intestinal digestion of acylglycerols are mediated by physiological detergents -- including bile salts, fatty acids, monoglycerides, and phospholipids. Each set of events relies on the formation of molecular aggregates, so that efficient transport and enzymatic hydrolysis may be accomplished. In order to develop a detailed molecular understanding of these processes, it is proposed to conduct a series of spectroscopic investigations that coordinate structural information on model digestive mixtures with their functions in the gastrointestinal tract. The dynamic structure of model biliary mixtures will be investigated with two-dimensional nuclear magnetic resonance (NMR) relaxation experiments: lipid-lipid arrangements, molecular mobility, and bilayer ordering will be assessed and correlated with enzymatic accessibilities. In lipid mixtures tat mimic three stages of glyceride digestion, quasielastic light scattering and 13C NMR measurements will be employed to delineate the size and surface features that make these substrates so susceptible to attack by the lipase-colipase system. Finally, attention will be focused explicitly on the conformation of colipase and its complexes with bile salt detergents, using a battery of 2D NMR techniques.