Characterization and binding properties of fatty acid-binding proteins from human, pig, and rat heart.
Fatty acid-binding proteins (FABPs) were isolated from the cytosols of hearts of man, pig, and rat by gel filtration and anion-exchange chromatography. The heart FABPs had a Mr of about 15,000 (pig, rat) and 15,500 (man); pI values were 5.2, 4.9, and 5.0 for human, pig, and rat heart, respectively. In contrast to liver FABPs, tryptophan was present in the heart FABPs. Binding characteristics for long-chain fatty acids determined with the radiochemical Lipidex assay were comparable for all three proteins. Heart FABPs also bind palmitoyl-CoA and -carnitine with an affinity comparable to that for palmitic acid. Other ligands investigated, heme, bilirubin, cholesterol, retinoids, and prostaglandins, could not compete with oleic acid for binding by human heart FABP. Binding parameters of FABP for oleic acid from multilamellar liposomes were comparable to those from the Lipidex binding assay. Immunological interspecies cross-reactivity with antisera against the heart FABPs was much higher between man and pig than between rat and man or pig. None of the antisera reacted with liver FABPs. The IgG fraction of anti-human heart FABP serum inhibited fatty acid binding to human heart FABP.
Paulussen
R J
RJ
Department of Biochemistry, University of Nijmegen, The Netherlands.
van der Logt
C P
CP
Veerkamp
J H
JH
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001667:Binding, Competitive; D002352:Carrier Proteins / Q000378:metabolism*; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003600:Cytosol / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000378:metabolism; D006801:Humans; D007526:Isoelectric Point; D008081:Liposomes / Q000378:metabolism; D008297:Male; D008970:Molecular Weight; D009206:Myocardium / Q000032:analysis*; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D019301:Oleic Acid; D009829:Oleic Acids / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013045:Species Specificity; D013552:Swine; D025521:Tumor Suppressor Proteins
D000596:Amino Acids; D002352:Carrier Proteins; C107608:FABP7 protein, human; C490174:Fabp7 protein, rat; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D008081:Liposomes; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D009829:Oleic Acids; D025521:Tumor Suppressor Proteins; D019301:Oleic Acid