Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University, West Lafayette, Indiana, United States of America.
PLoS One. 2012;7(5):e35473. doi: 10.1371/journal.pone.0035473. Epub 2012 May 1.
For starch digestion to glucose, two luminal α-amylases and four gut mucosal α-glucosidase subunits are employed. The aim of this research was to investigate, for the first time, direct digestion capability of individual mucosal α-glucosidases on cooked (gelatinized) starch. Gelatinized normal maize starch was digested with N- and C-terminal subunits of recombinant mammalian maltase-glucoamylase (MGAM) and sucrase-isomaltase (SI) of varying amounts and digestion periods. Without the aid of α-amylase, Ct-MGAM demonstrated an unexpected rapid and high digestion degree near 80%, while other subunits showed 20 to 30% digestion. These findings suggest that Ct-MGAM assists α-amylase in digesting starch molecules and potentially may compensate for developmental or pathological amylase deficiencies.
为了将淀粉消化成葡萄糖，需要两种肠腔α-淀粉酶和四种肠黏膜α-葡萄糖苷酶亚基。本研究的目的是首次研究单个肠黏膜α-葡萄糖苷酶对煮熟（胶凝）淀粉的直接消化能力。用不同量和消化时间的重组哺乳动物麦芽糖酶-葡糖淀粉酶（MGAM）的 N 端和 C 端亚基以及蔗糖酶-异麦芽糖酶（SI）消化胶凝正常玉米淀粉。在没有α-淀粉酶的帮助下，Ct-MGAM 出人意料地快速和高度消化，接近 80%，而其他亚基的消化率为 20%至 30%。这些发现表明 Ct-MGAM 辅助α-淀粉酶消化淀粉分子，并且可能潜在地补偿发育或病理淀粉酶缺乏。
