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， 磷脂 每一组事件都依赖于 双分子层或胶束聚集体，因此有效的运输和 可以完成酶水解。 为了开发 详细的分子理解这些过程，它提出 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。 的动力结构 模型胆道系统将研究与多场核 核磁共振（NMR）技术：13 C、2H和1H自旋 弛豫时间和（二维）核Overhauser效应 将被监测和理论上解释为两个简单的， 混合脂质胶束和囊泡。 在消化混合物中， 模拟脂肪餐后的十二指肠内容物，聚集结构， 对酶水解的敏感性将在 与13 C NMR、准弹性光 散射（QLS）和动力学方法。 最后，注意力将 明确地专注于蛋白质构象， 溶液状态核磁共振研究的胆盐结合。

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 bilayer or micelle 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 systems will be studied with multiple-field nuclear magnetic resonance (NMR) techniques: 13C, 2H, and 1H spin relaxation times and (two-dimensional) nuclear Overhauser effects will be monitored and interpreted theoretically for both simple and mixed lipid micelles and vesicles. In digestive mixtures that mimic duodenal content after a fatty meal, aggregate structure and susceptibility to enzymatic hydrolysis will be investigated in parallel with a combination of 13C NMR, quasielastic light scattering (QLS), and kinetic methods. Finally, attention will be focused explicitly on protein conformation with a series of solution-state NMR studies of colipase-bile salt binding.