Co-Investigator(Kenkyū-buntansha) |
OCHIAI Yoshihiro Ibaraki Univ., Faculty of Education, Associate Professor, 教育学部, 助教授 (50160891)
KIKUCHI Kiyoshi Graduate School of Agriculture and Life Sciences, THE UNIVERSITY OF TOKYO Assistant, 大学院・農学生命科学研究科, 助手 (20292790)
ABE Hiroki Agriculture and Life Sciences, THE UNIVERSITY OF TOKYO Professor, 大学院・農学生命科学研究科, 教授 (80086727)
MOTOKI Masao Ajinomoto Co.Ltd., Food Research Institute, Head, 原料素材基盤研究所, 所長(研究職)
ISHIZAKI Shoichiro Tokyo Univ. of Fisheries, Assistant Professor, 助手 (40251681)
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Research Abstract |
Myosin is a major muscle protein and responsible for fish meat gel formation in accompany with heat treatment. Such gel forming ability is dependent largely on fish species, but mechanisms involved in such species-specificity have remained unknown. This research project was performed aiming the improvement of quality for surimi-based products. The gel forming pattern for white croaker Pennahia argentata was different from that of walleye pollack Theragra chalcograma, the former quality being much better than that of the latter. Then, the primary structures of myosin heavy chain subunit was determined for white croaker and walleye pollack by cDNA cloning, and were found to contain 1,930 and 1,937, respectively. Gel formation of white croaker meat was slow at 20 to 30℃ and high and effective over 40℃ in white croaker meat. Tropomyosin from white croaker which was determined for its primary structure by cDNA cloning, showed high amino acid sequence identity to rabbit alpha tropomyosin. Myosin and its rod were prepared from white croaker and subjected to viscoelastic measurements. The storage modulus (G'), a parameter for gel formation, was increased at 30 to 42℃, decreased at 42 to 48℃, and increased again at 48 to 55℃. L-meromyosin (LMM), a half region of myosin rod in the C-terminal side, was produced by a genetically engineering method using recombinant DNA in E.coli for white croaker. Recombinant LMM showed endothermic peak at 31.7℃ in Differential scanning calorimetry (DS) C runs due to unfolding of alpha helix that was demonstrated by CD spectroscopy.
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