Molecular mechanism of autocatalytic processing of γ-glutamyltranspeptidase

γ-谷氨酰转肽酶自催化加工的分子机制

• 批准号: 13660090
• 负责人: SUZUKI Hideyuki
• 金额: $ 2.3万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13660090/
• 关键词: glutathione; γ-glutamyltransferase; γ-glutamyltranspeptidase; autocatalytic processing; processing; post-translational processing; プロセッシング

γ-Glutamyltranspeptidase is the key enzyme in glutathione metabolism and we previously presented evidence suggesting that it belongs to the N-terminal nucleophile hydrolase superfamily. Enzymatically active γ-glutamyltranspeptidase, which consists of one large subunit and one small subunit, is generated from an inactive common precursor through post-translational proteolytic processing. The processing mechanism for γ-glutamyltranspeptidase of Escherichia coli K-12 has been analyzed by means of in vitro studies using purified precursors. We here show that the processing of a precursor of γ-glutamyltranspeptidase is an intramolecular autocatalytic event and that the catalytic nucleophile for the processing reaction is the oxygen atom of the side-chain of Thr-391 (N-terminal residue of the small (β) subunit), which is also the nucleophile for the enzymatic reaction.

γ-谷氨酰转肽酶是谷胱甘肽代谢中的关键酶，我们之前提出的证据表明它属于 N 末端亲核水解酶超家族，具有酶活性，由一个大亚基和一个小亚基组成，是由非活性酶产生的。通过翻译后蛋白水解加工的共同前体 γ-谷氨酰转肽酶的加工机制。通过使用纯化前体的体外研究对大肠杆菌 K-12 进行了分析，我们在此表明​​，γ-谷氨酰转肽酶前体的加工是分子内自催化事件，并且加工反应的催化亲核试剂是 的氧原子。 Thr-391 的侧链（小 (β) 亚基的 N 端残基），也是酶促反应的亲核体反应。

项目成果

H. Suzuki, S. Izuka, N. Miyakawa, and H. Kumagai: "Enzymatic production of theanine, as "umami" component of tea, from glutamine and ethylamine with bacterial γ-glutamyltranspeptidase"Enzyme Microb. Technol.. 31(6). 884-889 (2002)

H. Suzuki、S. Izuka、N. Miyakawa 和 H. Kumagai：“用细菌 γ-谷氨酰转肽酶从谷氨酰胺和乙胺酶促生产茶氨酸，作为茶的“鲜味”成分”Enzyme Microb.. 31(6) ）884-889（2002）。

H.Suzuki, Y.Kajimoto, H.Kumagai: "Improvement of the bitter taste of amino acids through the transpeptidation reaction of bacterial γ-glutamyltranspeptidase"J. Agric. Food Chem.. 50(2). 313-318 (2002)

H.Suzuki，Y.Kajimoto，H.Kumagai：“通过细菌γ-谷氨酰转肽酶的转肽反应改善氨基酸的苦味”J.Agric. 50(2)。

H.Suzuki, N.Miyakawa, H.Kumagai: "Enzymatic production of γ-L-glutamyltaurine through the transpeptidation reaction of γ-glutamyltranspeptidase from E. coli K-12"Enzyme and Microbial Technology. (in press). (2002)

H.Suzuki、N.Miyakawa、H.Kumagai：“通过大肠杆菌 K-12 的 γ-谷氨酰转肽酶的转肽反应酶促生产 γ-L-谷氨酰牛磺酸”（酶和微生物技术）（2002 年出版）。

H. Suzuki, Y Kajimoto, and H. Kumagai: "Improvement of the bitter taste of amino acids through the transpeptidation reaction of bacterial γ-glutamyltranspeptidase"J. Agric. Food Chem.. 50(2). 313-318 (2002)

H. Suzuki、Y Kajimoto 和 H. Kumagai：“通过细菌 γ-谷氨酰转肽酶的转肽反应改善氨基酸的苦味”J. Agric. 50(2) (2002)。

鈴木秀之, 熊谷英彦: "γ-グルタミルトランスペプチダーゼ:Ntn-ヒドロラーゼスーパーファミリーの新しいメンバー"蛋白質 核酸 酵素. 46(11). 105-111 (2001)

Hideyuki Suzuki、Hidehiko Kumagai：“γ-谷氨酰转肽酶：Ntn-水解酶超家族的新成员”蛋白质核酸酶 46(11)。