title: Effect on ligand binding of arginine mutations in recombinant rat liver fatty acid-binding protein.
abstract: Rat liver fatty acid-binding protein is able to accommodate a wide range of non-polar anions in addition to long-chain fatty acids. The two arginine residues of rat liver fatty acid-binding protein, Arg122 and Arg126, have been mutated and the effect of mutation on ligand binding investigated. No significant decrease in affinity for the fluorescent fatty acid analogue, 11-(5-dimethylaminonaphthalenesulphonyl amino)undecanoic acid, or oleate was observed. However, the apparent affinity for oleoyl-CoA was slightly increased with the mutations Ala122 and Gln122 such that oleoyl-CoA rather than oleate became the preferred ligand for these mutants. Small changes in protein stability were observed with the Arg122 mutations. The lack of notable ionic involvement of the conserved internal residue Arg122 in ligand binding is consistent with the hypothesis that the mode of ligand binding in liver fatty acid-binding protein is markedly different from that of other members of this lipid-binding protein family.
authors.affiliation: Department of Biochemistry, University of Southampton, U.K.
authors.forename: A E
authors.initials: AE
authors.lastname: Thumser
authors.forename: C
authors.initials: C
authors.lastname: Evans
authors.forename: A F
authors.initials: AF
authors.lastname: Worrall
authors.forename: D C
authors.initials: DC
authors.lastname: Wilton
mesh_terms: D000214:Acyl Coenzyme A / Q000494:pharmacology; D000818:Animals; D001120:Arginine; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism*; D003545:Cysteine / Q000737:chemistry; D003619:Dansyl Compounds / Q000378:metabolism*; D004228:Dithionitrobenzoic Acid / Q000494:pharmacology; D004355:Drug Stability; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000378:metabolism; D008099:Liver / Q000737:chemistry*; D009154:Mutation; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D019301:Oleic Acid; D009829:Oleic Acids / Q000378:metabolism / Q000494:pharmacology; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013329:Structure-Activity Relationship
chemical_list: D000214:Acyl Coenzyme A; D002352:Carrier Proteins; D003619:Dansyl Compounds; C490174:Fabp7 protein, rat; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D005456:Fluorescent Dyes; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D009829:Oleic Acids; D011994:Recombinant Proteins; C017585:oleoyl-coenzyme A; D019301:Oleic Acid; C054400:11-(dansylamino)undecanoic acid; D001120:Arginine; D004228:Dithionitrobenzoic Acid; D003545:Cysteine