SPECTROSCOPIC STUDIES OF MODEL DIGESTIVE SYSTEMS

胆汁膜脂的分泌和肠道 乙酰甘油的消化是由生理洗涤剂介导的 包括胆盐、脂肪酸、单甘酯和 磷脂。每一组事件都依赖于 双层或胶束聚集体，从而有效地传输和 酶解可以完成。为了开发一种 提出了对这些过程的详细的分子理解 进行一系列光谱调查，以协调 关于模型消化混合物的结构信息及其 在胃肠道中起作用。的动态结构 模型胆道系统将用多野核素研究 核磁共振技术：13C、2H和1H自旋 弛豫时间与(二维)核Overhauser效应 将在理论上被监控和解释为简单和 混合脂质胶束和囊泡。在消化混合物中 模拟脂肪餐后十二指肠内容物、聚集结构和 对酶水解的敏感性将在 与13C核磁共振、准弹性光平行组合 散射(QLS)和动力学方法。最后，关注将会是 通过一系列明确关注蛋白质构象的 共脂肪酶-胆盐结合的溶液核磁共振研究。

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.