PROTEIN LIPID INTERACTIONS IN GALLSTONE PATHOGENESIS

胆固醇结石病是美国最常见的消化系统疾病之一，每年导致70万例胆囊切除术，直接医疗费用超过30亿美元。胆囊粘蛋白在胆结石形成中起核心作用，本研究将探讨粘蛋白与胆脂相互作用促进胆结石形成的机制。具体目的是：1)表征粘蛋白分子的特定位点与脂质囊泡的相互作用，以提高我们对粘蛋白如何促进一水胆固醇结晶的理解；2)描述黏液蛋白如何影响溶液和凝胶中晶体的形态和生长速率，从而最终开发出生长抑制剂；3)检查黏液蛋白作为基质蛋白在钙和胆固醇的生物矿化中的核心作用。这些目标将通过利用多种生物物理技术来检查模型系统，其中粘蛋白及其修饰的结构形式将与胆脂相互作用，类似于胆石胆汁。荧光分析、动态光散射和魔角旋转磁共振将研究粘蛋白如何促进囊泡融合和亚微观成核。光镜和电子显微镜将检查粘蛋白如何促进晶体生长的模式和速度。这些研究可能会导致这种非常常见的疾病的预防和非手术治疗策略。

Cholesterol gallstone disease is one of the commonest digestive diseases in the United States and results in 700,000 cholecystectomies annually with a direct health care cost in excess of $3 billion. Gallbladder mucin plays a central role in gallstone formation and this proposal will examine the mechanism by which mucin interacts with biliary lipids to promote gallstones. The specific Aims are to 1) Characterize the interaction of specific sites of the mucin molecule with lipid vesicles to improve our understanding of how mucin promotes crystallization of cholesterol monohydrate; 2) Characterize how mucin effects the morphology and rate of crystal growth in solution and in gels so that growth inhibitors can eventually be developed; 3) Examine the central role of mucin as the matrix protein in the biomineralization of both calcium and cholesterol. These Aim's will be achieved by utilizing multiple biophysical techniques to examine model systems where mucin and its modified structural forms will interact with biliary lipids similar to those seen in gallstone bile. Fluorescent assays, dynamic light scattering and magic angle spinning magnetic resonance will examine how mucin promotes vesicle fusion and sub- microscopic nucleation. Light and electron microscopy will examine the way in which mucin can promote both the pattern and rate of crystal growth. These studies may lead to strategies for the prevention and non-surgical therapy of this very common disease.