促成核泡相糖蛋白的分离、纯化及理化性质研究  

Purification and Characterization of A Nucleation-Promoting Vesicular Glycop rotein

作　　者：项建斌[1] 蔡端[1] 张延龄[1] 查锡良[2] 

机构地区：[1]复旦大学附属华山医院外科,200040 [2]复旦大学上海医学院生物化学与分子生物学系,上海200032

出　　处：《复旦学报（医学版）》2005年第3期333-336,共4页Fudan University Journal of Medical Sciences

基　　金：国家自然科学基金 (3 0 0 70 73 7);卫生部基金 (98 2 12 4)项目资助

摘　　要：目的　提纯胆汁泡相糖蛋白并研究其理化性质。方法　应用超速离心法结合高效液相层析(HPLC)分离纯化胆汁泡相糖蛋白,体外观察成核活性,并检测泡相糖蛋白的相对分子质量和化学组成。结果　胆汁泡相糖蛋白Mr 约为335 0 0 ,具有较强的促成核功能,成核活性达0 .31。泡相糖蛋白由多肽和寡糖组成,糖-肽键为N -连接方式,其中多肽Mr 约为2 10 0 0 ,含15 3个氨基酸,包括97个极性氨基酸和5 6个非极性氨基酸。糖链约占总蛋白含量的37.3% ,为核心岩藻糖丰富的多天线复杂型聚糖。肽链N -末端氨基酸序列为H2 N -天冬 天冬酰胺 -丝 -谷氨酰胺- 组-精- 酪- 缬- 苯丙- 异亮氨酸。结论　胆汁泡相糖蛋白是一种新的促成核活性因子,在胆固醇性结石的早期发生阶段可能起重要作用。Purpose To purify and partially character ize the nucleation-promoting vesicular glycoprotein from bile. Methods Vesicular glycoprotein was extracted by ultrace ntrifugation and high-performance li-quid chromatography (HPLC).The nucleation - promoting activity was detected in vitro and its relative mole-cular weight and polypeptide and carbohydrate components were also analyzed. Results The vesicular glycoprotein with molecular weigh t of 33 500 dalton exhibited a potent pro-nucleating activity in model bile and it was composed of polypeptide containing 97 polar amino acids and 56 non-pola r amino acids and was an extensively glycosylated (37.3%) monomer.The type of li nkage between polypeptide and carbohydrate components was N-linkage mode.N-ter minal amino acid sequence of the vesicular protein was Asp-Asn-Ser-Gln-His- Arg-Tyn-Val-Phe-Ile. Conclusion These data suggestted that the vesicular pro tein may be a novel pro-nucleating glycoprotein which functions in the early st age of the pathogenesis of cholesterol gallstone disease.

关 键 词：胆汁 糖蛋白 泡 糖链 

分 类 号：R446.61[医药卫生—诊断学]