title: Molecular characterization of southern bluefin tuna myoglobin (Thunnus maccoyii).
abstract: The primary structure of southern bluefin tuna Thunnus maccoyii Mb has been elucidated by molecular cloning techniques. The cDNA of this tuna encoding Mb contained 776 nucleotides, with an open reading frame of 444 nucleotides encoding 147 amino acids. The nucleotide sequence of the coding region was identical to those of other bluefin tunas (T. thynnus and T. orientalis), thus giving the same amino acid sequences. Based on the deduced amino acid sequence, bioinformatic analysis was performed including phylogenic tree, hydropathy plot and homology modeling. In order to investigate the autoxidation profiles, the isolation of Mb was performed from the dark muscle. The water soluble fraction was subjected to ammonium sulfate fractionation (60-90 % saturation) followed by preparative gel electrophoresis. Autoxidation profiles of Mb were delineated at pH 5.6, 6.5 and 7.4 at temperature 37 °C. The autoxidation rate of tuna Mb was slightly higher than that of horse Mb at all pH examined. These results revealed that tuna myoglobin was unstable than that of horse Mb mainly at acidic pH.
authors.affiliation: Department of Aquatic Product Technology, Faculty of Fisheries and Marine Sciences, Bogor Agricultural University, Bogor, Indonesia. malanm28@gmail.com.
authors.forename: Mala
authors.initials: M
authors.lastname: Nurilmala
authors.affiliation: Laboratory of Aquatic Bioresource Chemistry, Graduate School of Agricultural Science, Tohoku University, Sendai, 981-8555, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Ochiai
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D029941:Fish Proteins / Q000235:genetics*; D006863:Hydrogen-Ion Concentration; D009211:Myoglobin / Q000235:genetics*; D010084:Oxidation-Reduction; D010802:Phylogeny; D016415:Sequence Alignment; D014413:Tuna / Q000235:genetics*
chemical_list: D018076:DNA, Complementary; D029941:Fish Proteins; D009211:Myoglobin
keywords: Autoxidation profiles; Myoglobin; Southern bluefin tuna; cDNA cloning