Membrane-bound D-mannose isomerase of acetic acid bacteria: finding, characterization, and application.
Membrane-bound D-mannose isomerase of acetic acid bacteria: finding, characterization, and application.
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醋酸菌的膜结合 D-甘露糖异构酶：发现、表征和应用。
DOI：
10.1093/bbb/zbac049
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Toshiharu Yakushi.
中科院分区：
文献类型：
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作者：
Osao Adachi;Naoya Kataoka;Kazunobu Matsushita;Yoshihiko Akakabe;Toshihiro Harada;Toshiharu Yakushi.
在醋酸菌中发现了一种催化甘露糖和果糖可逆转化的甘露糖异构酶（EC 5.3.1.7）。细胞分离证实该酶是一种典型的膜结合酶，而迄今为止报道的所有糖异构酶都是细胞质的。该酶的最适pH值为5.5，与细胞质酶的碱性最适pH值形成鲜明对比。该酶对热稳定，最适反应温度为40-60 °C。从膜组分溶解后纯化的酶显示由48 kDa的相同4个亚基组成的196 kDa的总分子量。洗涤细胞或固定化细胞的功能良好，d-甘露糖转化为d-果糖的转化率接近80%，d-果糖转化为d-甘露糖的转化率在20%-25%之间。探讨了该酶的催化特性及其在芋头果葡糖浆生产中的应用。
d-Mannose isomerase (EC 5.3.1.7) catalyzing reversible conversion betweend-mannose andd-fructose was found in acetic acid bacteria. Cell fractionation confirmed the enzyme to be a typical membrane-bound enzyme, while all sugar isomerases so far reported are cytoplasmic. The optimal enzyme activity was found at pH 5.5, which was clear contrast to the cytoplasmic enzymes having alkaline optimal pH. The enzyme was heat stable, and the optimal reaction temperature was observed at around 40-60 °C. Purified enzyme after solubilization from membrane fraction showed the total molecular mass of 196 kDa composing of identical 4 subunits of 48 kDa. Washed cells or immobilized cells were well functional at nearly 80% of conversion ratio fromd-mannose tod-fructose and reversely 20%-25% ofd-fructose tod-mannose. Catalytic properties of the enzyme were discussed with respect to the biotechnological applications to high fructose syrup production from konjac taro.