Catala I, Domingo N, Juste C, Gueugneau A M, Thorin B, Lutton C, Corring T, Lafont H
Laboratoire d'Ecologie et de Physiologie du Système Digestif, INRA, 78352 Jouy-en-Josas Cedex, France.
Biochim Biophys Acta. 1998 Oct 2;1394(1):74-84. doi: 10.1016/s0005-2760(98)00101-5.
We explored the possibility that the biliary protein fraction may support part of the variation in the nucleating activity previously measured in gallbladder biles of pigs. Eighteen gallbladder aspirates freshly obtained from three dietary groups (0, 5, or 10% beta-cyclodextrin) of six pigs were chromatographed to purify their total protein fraction. Proteins were quantified, and analysed through electrophoresis and immunoblotting or enzyme-linked immunosorbent assay for albumin, and five putative effectors of cholesterol crystallisation, mucins, immunoglobulin A, 130 kDa, apolipoprotein A-I, and anionic polypeptide fraction. Each total protein fraction was also assayed for its ability to influence cholesterol precipitation, when added to supersaturated model bile. The current data provided evidence that the cholesterol crystallisation-promoting activity of biliary proteins in model biles increased with the beta-cyclodextrin dietary content. This occurred without any significant change in the total biliary protein content, but was associated with a significant decrease in the concentration of albumin and apolipoprotein A-I, resulting in changes in the overall balance of proteins in bile. Comparison of these results with the crystallisation figures previously obtained from the corresponding native biles led us to conclude that biliary proteins might influence the outcome of the crystallisation process, namely the final crystal concentration at equilibrium, but would not systematically represent a major driving force for determining the velocity of crystal formation in native bile of pigs.
我们探究了胆汁蛋白组分可能是先前在猪胆囊胆汁中测得的成核活性部分差异原因的可能性。从三个饮食组（0%、5%或10%β-环糊精）的六头猪新鲜获取的18份胆囊抽吸物进行色谱分析，以纯化其总蛋白组分。对蛋白质进行定量，并通过电泳、免疫印迹或酶联免疫吸附测定法分析白蛋白以及胆固醇结晶的五种假定效应物、粘蛋白、免疫球蛋白A、130 kDa蛋白、载脂蛋白A-I和阴离子多肽组分。当将每个总蛋白组分添加到过饱和模型胆汁中时，还检测其影响胆固醇沉淀的能力。目前的数据表明，模型胆汁中胆汁蛋白促进胆固醇结晶的活性随β-环糊精饮食含量的增加而增加。这种情况在总胆汁蛋白含量没有任何显著变化的情况下发生，但与白蛋白和载脂蛋白A-I浓度的显著降低有关，导致胆汁中蛋白质的整体平衡发生变化。将这些结果与先前从相应天然胆汁中获得的结晶数据进行比较，我们得出结论，胆汁蛋白可能会影响结晶过程的结果，即平衡时的最终晶体浓度，但不会系统地成为决定猪天然胆汁中晶体形成速度的主要驱动力。
