胆汁泡蛋白成核活性及其氨基酸序列分析的研究

Study on the Nucleating Activity and Amino-acids: Sequence of Biliary Vesicular Protein(s)

分离胆汁泡蛋白,研究其成核活性和末端氨基酸序列。方法:应用超速离心法分离胆石症患者胆汁泡,运用SDS-PAGE电泳分离其中胆汁泡蛋白,并经HPLC系统纯化,研究其成核活性和N-端氨基酸序列。结果:分离到一种分子量为33.5kd的胆汁泡蛋白,其促成核活性为0.30,N-端氨基酸具有较多的极性氨基酸(天冬酰、苏、丝和谷氨酰等)。结论:33.5kd胆汁泡蛋白有明显的促成核活性,其N-端极性氨基酸可能参与促成核机制。

To isolate biliary vesicular protein(s) and to determine its nucleating activity and ami-no acids sequence. Methods: Biliary vesicules were isolated by ultracentrifugation, and their vesicular protein(s) isolated by SDS-PAGE and purified by HPLC. The nucleating activity was determined by the nucleation-time method. Results: We succeeded in isolating a 33.5kd vesicular protein with a potent cholesterol-pronucleating activity; amino acids analysis revealed its NH2-terminals contained more po-lar amino acids, such as asparagine, threonine, serine and glutamine. Conclusions: The 33.5kd ves-icular protein possesses a potent pronucleating activity. It plays a role in the pathogenesis of gallstone formation, possibly by its NH2-terminal polar amino acids.