Beckett G J, Armstrong P, Percy-Robb I W
Biochim Biophys Acta. 1981 Jun 23;664(3):602-10. doi: 10.1016/0005-2760(81)90136-3.
The binding of bile salts to proteins in rat plasma and rat lymph has been investigated. Under the non-equilibrium conditions of gel chromatography no binding of glycochenodeoxycholate or glycocholate to any of the lymph proteins was observed. In contrast, plasma bound a proportion of both bile salts. When lymph was treated with charcoal, binding of glycochenodeoxycholate to a protein with a molecular weight identical to albumin occurred. Equilibrium binding studies showed that the binding of glycocholate to partially purified plasma albumin exhibited saturation kinetics with a dissociation constant of 2 x 10(-4) M. In contrast, the binding of glycocholate to lymph albumin was non-saturable. Potassium oleate, when added to plasma in a free fatty acid : albumin molar ratio of 3.8 : 1, almost completely inhibited the binding of chenodeoxycholate to plasma albumin. The endogenous free fatty acid : albumin ratios found in systemic plasma and lymph were 0.6 : 1 and 9.2 : 1, respectively. It is suggested that the high free fatty acid concentrations found in lymph inhibit the binding of bile salts to albumin.
对大鼠血浆和大鼠淋巴液中胆汁盐与蛋白质的结合情况进行了研究。在凝胶色谱的非平衡条件下，未观察到甘氨鹅脱氧胆酸盐或甘胆酸盐与任何淋巴液蛋白质的结合。相比之下，血浆结合了一定比例的两种胆汁盐。当用活性炭处理淋巴液时，甘氨鹅脱氧胆酸盐与一种分子量与白蛋白相同的蛋白质发生了结合。平衡结合研究表明，甘胆酸盐与部分纯化的血浆白蛋白的结合呈现饱和动力学，解离常数为2×10⁻⁴ M。相比之下，甘胆酸盐与淋巴白蛋白的结合是不饱和的。当以游离脂肪酸∶白蛋白摩尔比3.8∶1向血浆中添加油酸钾时，几乎完全抑制了鹅脱氧胆酸盐与血浆白蛋白的结合。在全身血浆和淋巴液中发现的内源性游离脂肪酸∶白蛋白比值分别为0.6∶1和9.2∶1。提示淋巴液中发现的高游离脂肪酸浓度抑制了胆汁盐与白蛋白的结合。
