胆石症患者与正常人胆汁33500泡蛋白成核活性的比较

Cholesterol nucleation-promoting activity of the 33 500 vesicular protein in the bile from normal individuals and patients with cholesterol gallstone

目的比较胆石症患者与正常人的胆汁33 500泡蛋白成核活性。方法利用超速离心法从正常人及胆石症患者胆汁中纯化33 500泡蛋白,采用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳鉴定其纯化效果。通过Holan法测定成核时间,计算成核活性。结果胆石症患者的33 500泡蛋白平均成核时间为(3.8±0.7)d,成核活性中位数达0.303,具有强促成核作用,能显著缩短成核时间,促进胆固醇结晶形成。而正常人促成核作用较弱,平均成核时间为(8.4±0.9)d,成核活性中位数仅为0.667。胆石症患者与正常人胆汁33 500泡蛋白平均成核时间及促成核活性的差异均有统计学意义(P值均<0.05)。结论与正常人相比,胆石症患者的胆汁33 500泡蛋白促成核活性明显增强。

Objective To compare the cholesterol nucleation-promoting activities of the 33 500 vesicular protein in fresh bile from normal individuals and patients with cholesterol gallstone disease. Methods The 33 500 vesicular protein was isolated by discontinuous gradient ultracentrifugation from fresh bile samples from normal individuals and patients with cholesterol gallstone disease. SDS-PAGE was used to identify the purification of the 33 500 vesicular protein, and the protein samples from different individuals were added into the simulated preparation of the native bile to determine their respective nucleation time with a sensitive cholesterol crystal growth assay. Results The average nucleating time determined by Holan method of the 33 500 vesicular protein from the gallstone patients was （3.8±0.7） days; the protein possessed a strong nucleation-promoting activity （0. 303） and a capacity of significantly shortening the nucleation time to accelerate the formation of cholesterol crystal. The 33 500 vesicular protein from normal individuals showed weak capacity of promoting nucleation, with the average nucleation time（NT） of （8.4 ±0.9） days and a nucleation-promoting activity of 0. 677, even lower than the glycoproteins of 7 000（0. 564）, 13 000（0. 419）, and 20 000（0. 356）. Conclusion Compared with normal individuals, patients with cholesterol gallstones have increased concentration of the 33 500 vesicular protein in the bile, and this protein from the patients possesses stronger nucleation-promoting activity.