Nishimoto So, Debarbat Anaïs, Ikeda Yuki, Arikawa Emi, Odagaki Yuki, Yano Haruna, Qiao Ying, Ito Masaaki, Kimura Toshiyuki, Takita Teisuke, Yasukawa Kiyoshi
Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
Department of Bioresources Engineering, National Institute of Technology, Okinawa College, Henoko, Nago 905-2192, Japan.
J Agric Food Chem. 2025 Jan 8;73(1):617-624. doi: 10.1021/acs.jafc.4c06902. Epub 2024 Dec 23.
In mammals, intestinal α-glucosidase exists as a maltase-glucoamylase complex (MGAM) and a sucrase-isomaltase complex (SI). In this study, we transiently expressed human MGAM and SI in human embryonic kidney 293 (HEK293) cells. At pH 6.0 and 37 °C, the MGAM-expressing HEK293 cells extract (MGE) exhibited maltase, glucoamylase, and isomaltase activities but not sucrase activity, whereas the SI-expressing HEK293 cells extract (SIE) exhibited sucrase, isomaltase, and maltase activities but not glucoamylase activity. The apparent value of the MGE for maltose hydrolysis was 14-26% of that of the SIE for maltose, sucrose, and isomaltose hydrolysis. The respective apparent values of the MGE and SIE for sucrose and isomaltose hydrolysis were 0% and 6% and 10% and 42% of those for maltose hydrolysis. These results indicated that the maltase activities of MGAM and SI were higher than those of sucrase and isomaltase.
在哺乳动物中，肠道α-葡萄糖苷酶以麦芽糖酶-葡糖淀粉酶复合物（MGAM）和蔗糖酶-异麦芽糖酶复合物（SI）的形式存在。在本研究中，我们在人胚肾293（HEK293）细胞中瞬时表达了人MGAM和SI。在pH 6.0和37°C条件下，表达MGAM的HEK293细胞提取物（MGE）表现出麦芽糖酶、葡糖淀粉酶和异麦芽糖酶活性，但没有蔗糖酶活性，而表达SI的HEK293细胞提取物（SIE）表现出蔗糖酶、异麦芽糖酶和麦芽糖酶活性，但没有葡糖淀粉酶活性。MGE对麦芽糖水解的表观 值是SIE对麦芽糖、蔗糖和异麦芽糖水解表观 值的14%-26%。MGE和SIE对蔗糖和异麦芽糖水解的各自表观 值分别是对麦芽糖水解表观 值的0%和6%以及10%和42%。这些结果表明，MGAM和SI的麦芽糖酶活性高于蔗糖酶和异麦芽糖酶的活性。
