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University of the Ryukyus Repository >
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The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus >
No.26 (1979/12) >
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| Title | : | 泡盛酵母の L-ロイシン : α-ケトグルタル酸トランスアミナーゼ(農芸化学科) |
| Title alternative | : | L-Leucine : α-ketoglutarate transaminase of the strain AY-634 of awamori yeast (Department of Agricultural Chemistry) |
| Authors | : | 当山, 清善
与那覇, 和雄
石原, 昌信
儀間, 勝 |
| Authors alternative | : | Toyama, Seizen
Yonaha, Kazuo
Ishihara, Masanobu
Gima, Masaru |
| Issue Date | : | 11-Dec-1979 |
| Abstract | : | 酵母のL-ロイシン : α-ケトグルタル酸トランスアミナーゼ活性を調べた結果, 本酵素活性が各種の醸造用酵母に存在することがわかった。高い活性が泡盛醪から分離された泡盛酵母AY-634菌株で得られたので, 本菌株を用いて酵素の性質を調べた。本菌株をペプトンーグルコース培地で振とう培養してえた菌体の無細胞抽出液はL-ロイシンとα-ケトグルタル酸からL-グルタミン酸とα-ケトイソカプロン酸を生成するアミノ基転移反応を触媒した。培地にL-ロイシンを加えても活性の増加はみられなかったが, 本菌株を麹抽出液培地で培養すると高い活性が得られた。本酵素はL-イソロイシン, L-バリン, L-スレオニンおよびL-フェニールアラニンのアミノ基転移反応も触媒した。本酵素の反応至適pHは8.0で, 至適温度は40℃であった。本酵素はピリドキサールー5'-リン酸の存在下で熱に安定であった。
The activity of L-leucine : α-ketoglutarate transaminase was distributed in various strains of brewer's yeasts. A high activity of the enzyme was found in the strain AW-634 of awamori yeast isolated from awamori mash, and the strain was chosen for characterization of the enzyme. The cell-free extract of the strain grown on peptone-glucose medium with shaking catalyzed the transamination reaction between L-leucine and α-ketoglutarate to produce L-glutamate and α-ketoisocaproate. The enzyme activity was not enhanced by addition of L-leucine to the medium. When the strain was grown on koji-extract medium with stationary culture, the strong activity was obtained. The enzyme also catalyzed the transamination of L-isoleucine, L-valine, L-threonine and L-phenylalanine to α-ketoglutarate. The pH and temperature optima for the activity were 8.0 and 45℃, respectively. The enzyme was heat stable at pH 8.0 in the presence of pyridoxal 5'-phosphate. |
| Type Local | : | 紀要論文 |
| ISSN | : | 0370-4246 |
| Publisher | : | 琉球大学農学部 |
| URI | : | http://hdl.handle.net/20.500.12000/4152 |
| Citation | : | 琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus no.26 p.125 -133 |
| Appears in Collections | : | No.26 (1979/12)
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