Hepatic fatty acid-binding proteins of a teleost, Lateolabrax japonicus. The primary structures and location of a disulfide bond.
Two fatty acid-binding proteins (FABP), FABP-1 and FABP-2, were purified from the liver cytosol of the teleost, Lateolabrax japonicus (Japan sea bass), and characterized. The complete primary structure of FABP-2 was determined by protein analysis to be the following: MDFSGTWQVY AQENYEEFLR AMELPADVIK MAKDIKPITE IKQSGNDFVV TSKTPGKTVT NSFTIGKEAD ITTMDGKKIR CVVNLEGGKL VCNTGKFCHI QELRGGEMVE TLTMGSTTLI RKSKKM. Partial peptide sequences of FABP-1 were also determined. Phylogenetic analysis indicates that FABP-2 is a homologue of mammalian hepatic FABP, whereas FABP-1 is most similar to the members of mammalian cardiac FABP subfamily. L. japonicus FABP-2 contains three cysteine residues, and a disulfide bond is identified between Cys-81 and Cys-92. A theoretical model of FABP-2 generated by a homology modeling method indicates close proximity of the two cysteine residues in the three-dimensional structure. This is a rather rare case of cytosolic protein having a disulfide bond under the normally reducing conditions of the cytosol, though the presence or absence of disulfide bonds does not seem to affect the ligand-binding ability.
Odani
S
S
Department of Biology, Faculty of Science, Niigata University, Ikarashi, Niigata 950-2181, Japan. sodani@sc.niigata-u.ac.jp
Baba
K
K
Tsuchida
Y
Y
Aoyagi
Y
Y
Wakui
S
S
Takahashi
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism; D004220:Disulfides / Q000737:chemistry; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000378:metabolism; D029941:Fish Proteins; D008099:Liver / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins; D010473:Perciformes / Q000378:metabolism*; D010802:Phylogeny; D011487:Protein Conformation; D020539:Sequence Analysis, Protein
D002352:Carrier Proteins; D004220:Disulfides; C425124:FABP-1 protein, Lateolabrax japonicus; C493320:Fabp1 protein, mouse; C493405:Fabp2 protein, mouse; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D029941:Fish Proteins; D009363:Neoplasm Proteins