Division of Applied Biology, Kyoto Institute of Technology, Goshokaido-cho, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan.
J Agric Food Chem. 2021 Jul 14;69(27):7675-7679. doi: 10.1021/acs.jafc.1c02535. Epub 2021 Jun 29.
γ-Glutamylvalylglycine is known as a potent "" substance that increases the thickness, continuity, and mouthfulness of the taste of food. In this study, γ-glutamylvalylglycine was enzymatically synthesized from glutamine and valylglycine through the transpeptidation reaction of bacterial γ-glutamyltranspeptidase. The reaction conditions decided for the production of γ-glutamylvalylglycine are 20 mM glutamine, 100 mM valylglycine, 30 mU/mL γ-glutamyltranspeptidase, and 0.856 M (5%) NaCl at pH 8 and 37 °C, and 18.6 mM γ-glutamylvalylglycine was synthesized. Metal cations, Na and Mg, improved the transpeptidation reaction of γ-glutamyltranspeptidase, and the production of γ-glutamylvalylglycine increased. Moreover, by feeding a suitable amount of glutamine every 5 h, the maximum production of γ-glutamylvalylglycine increased 1.7 times after 20 h of incubation.
γ-谷氨酰缬氨酰甘氨酸是一种强效的“增味物质”，可增加食物的厚度、连续性和口感浓郁度。在这项研究中，通过细菌谷氨酰转肽酶的转肽反应，从谷氨酰胺和缬氨酰甘氨酸酶促合成了γ-谷氨酰缬氨酰甘氨酸。决定γ-谷氨酰缬氨酰甘氨酸生产的反应条件为 20 mM 谷氨酰胺、100 mM 缬氨酰甘氨酸、30 mU/mL 谷氨酰转肽酶和 0.856 M（5%）NaCl，在 pH8 和 37°C 下合成了 18.6 mM γ-谷氨酰缬氨酰甘氨酸。金属阳离子 Na 和 Mg 可改善谷氨酰转肽酶的转肽反应，从而提高γ-谷氨酰缬氨酰甘氨酸的产量。此外，通过每 5 h 适量补加谷氨酰胺，在孵育 20 h 后，γ-谷氨酰缬氨酰甘氨酸的最大产量增加了 1.7 倍。
