阿尔法胰脏控制葡萄糖同化通过N-Glycan-specific十二指肠检索绑定,内吞作用和退化。

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日期K, Satoh Iida K,小川H

阿尔法胰脏控制葡萄糖同化通过N-Glycan-specific十二指肠检索绑定,内吞作用和退化。

J生物化学杂志。2015年7月10日,290 (28):17439 - 50。doi: 10.1074 / jbc.M114.594937。2015年5月28日Epub。

PubMed ID

26023238 (在PubMed

]

文摘

阿尔法淀粉酶是胰腺蛋白质和淀粉水解酶,主要能源收购至关重要。专门哺乳动物胰脏阿尔法结合糖蛋白N-glycans小肠膜激活淀粉消化,而它显著抑制葡萄糖吸收的钠(+)/葡萄糖转运蛋白1 (SGLT1)高浓度(Asanuma-Date K。Hirano, Y。勒,N。佐野K。川崎,N。Hashii, N。Hiruta, Y。中山,K。Umemura, M。石川,K。Sakagami, H。,小川,h(2012)功能监管的糖同化N-glycan-specific交互的阿尔法胰腺十二指肠刷状缘膜糖蛋白。生物。287年化学,23104 - 23118)。然而,如何抑制停止是未知的。 Here, we show a new mechanism for the regulation of intestinal glucose absorption. Immunohistochemistry revealed that alpha-amylase in the duodena of non-fasted, but not fasted, pigs was internalized from the pancreatic fluid and immunostained. We demonstrated that after N-glycan binding, pancreatic alpha-amylase underwent internalization into lysosomes in a process that was inhibited by alpha-mannoside. The internalized alpha-amylase was degraded, showing low enzymatic activity and molecular weight at the basolateral membrane. In a human intestinal Caco-2 cell line, Alexa Fluor 488-labeled pancreatic alpha-amylase bound to the cytomembrane was transported to lysosomes through the endocytic pathway and then disappeared, suggesting degradation. Our findings indicate that N-glycan recognition by alpha-amylase protects enterocytes against a sudden increase in glucose concentration and restores glucose uptake by gradual internalization, which homeostatically controls the postprandial blood glucose level. The internalization of alpha-amylase may also enhance the supply of amino acids required for the high turnover of small intestine epithelial cells. This study provides novel and significant insights into the control of blood sugar during the absorption stage in the intestine.

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药物酶

药物	酶	类	生物	药理作用	行动
Beta-D-Glucose	胰α淀粉酶	蛋白质	人类	未知的	底物	细节