Thumser A E, Wilton D C
Department of Biochemistry, University of Southampton, U.K.
Biochem J. 1996 Dec 15;320 ( Pt 3)(Pt 3):729-33. doi: 10.1042/bj3200729.
The physiological role of liver fatty acid-binding protein (L-FABP) has yet to be clarified. An important feature of this member of the family of intracellular lipid-binding proteins is the wide range of compounds that have been identified as potential physiological ligands. By using recombinant L-FABP, the binding of cholesterol, bile salts and their derivatives has been investigated under conditions that allow a direct comparison of the binding affinities of these ligands for fatty acids. The results demonstrate an inability of L-FABP to bind cholesterol, although the anionic derivative, cholesteryl sulphate, will bind under similar assay conditions. Of the bile salts examined, lithocholate and taurolithocholate sulphate showed the greatest binding to L-FABP. It is proposed that an important function of L-FABP is to bind certain physiological amphipathic anions, thus preventing the "free' concentrations of these compounds from exceeding their critical micelle concentration, which could result in cell damage.
肝脏脂肪酸结合蛋白（L-FABP）的生理作用尚未明确。细胞内脂质结合蛋白家族的这一成员的一个重要特征是，已被鉴定为潜在生理配体的化合物种类繁多。通过使用重组L-FABP，在能够直接比较这些配体与脂肪酸结合亲和力的条件下，研究了胆固醇、胆汁盐及其衍生物的结合情况。结果表明，L-FABP无法结合胆固醇，尽管其阴离子衍生物硫酸胆固醇能在类似的检测条件下结合。在所检测的胆汁盐中，石胆酸盐和牛磺石胆酸硫酸盐与L-FABP的结合力最强。有人提出，L-FABP的一个重要功能是结合某些生理性两亲阴离子，从而防止这些化合物的“游离”浓度超过其临界胶束浓度，否则可能导致细胞损伤。
