The binding of cholesterol and bile salts to recombinant rat liver fatty acid-binding protein.
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.
Thumser
A E
AE
Department of Biochemistry, University of Southampton, U.K.
Wilton
D C
DC
D000818:Animals; D001647:Bile Acids and Salts / Q000378:metabolism* / Q000494:pharmacology; D001667:Binding, Competitive; D002352:Carrier Proteins / Q000378:metabolism*; D002784:Cholesterol / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D003619:Dansyl Compounds / Q000378:metabolism; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism; D008081:Liposomes / Q000378:metabolism; D008099:Liver; D008958:Models, Molecular; D018996:Myelin P2 Protein / Q000378:metabolism*; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D011485:Protein Binding; D051381:Rats; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013261:Sterols / Q000378:metabolism / Q000494:pharmacology
D001647:Bile Acids and Salts; D002352:Carrier Proteins; D003619:Dansyl Compounds; C493320:Fabp1 protein, mouse; C493321:Fabp1 protein, rat; C490174:Fabp7 protein, rat; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D005456:Fluorescent Dyes; D008081:Liposomes; D018996:Myelin P2 Protein; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D011994:Recombinant Proteins; D013261:Sterols; C054400:11-(dansylamino)undecanoic acid; D002784:Cholesterol