The role of covalently bound fatty acids in the degradation of human gastric mucus glycoprotein.
The role of covalently bound fatty acids in the degradation of human gastric mucus glycoprotein.
复制标题
共价结合脂肪酸在人胃粘液糖蛋白降解中的作用。
DOI：
10.1016/0003-9861(84)90188-7
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发表时间：
1984
影响因子：
3.9
通讯作者：
Slomiany,BL
中科院分区：
文献类型：
--
作者：
Slomiany,A;Jozwiak,Z;Takagi,A;Slomiany,BL
经凝胶过滤、十二烷基硫酸钠-聚丙烯酰胺凝胶电泳法、氯化铯密度梯度离心法和脂类分析表明，未降解的人胃粘液高相对分子质量糖蛋白不含非共价结合蛋白和脂类。对脱脂糖蛋白进行温和的碱性甲醇分解，结果表明，天然未降解糖蛋白平均含有2.9摩尔的酰基连接脂肪酸/mg糖蛋白。经胃酶消化后得到的低分子糖蛋白亚基含有2nmoL的酰基连接脂肪酸/mg糖肽。共价结合脂肪酸的含量最高的部分是糖蛋白，经胃酶消化后仍未降解。平均而言，这种胃蛋白酶抗性糖蛋白的脂肪酸含量为10.2摩尔/毫克。在羟胺脱酰后，未降解的抗胃蛋白酶糖蛋白变得容易被蛋白水解性切割。这些结果表明，胃粘液糖蛋白共价结合的脂肪酸参与了胃粘液糖蛋白蛋白水解性消化的调节。
The undegraded high-molecular-weight glycoprotein of human gastric mucus has been isolated free of noncovalently bound proteins and lipids, as judged by gel filtration, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, cesium chloride density gradient centrifugation, and lipid analysis. Mild alkaline methanolysis of the thoroughly delipidated glycoprotein revealed that, on the average, the native undegraded glycoprotein contains 2.9 mol of acyl linked fatty acids/mg glycoprotein. The low-molecular-weight glycoprotein subunits, obtained after pepsin digestion, contain 2 nmol of acyl linked fatty acids/mg glycopeptide. The highest content of covalently bound fatty acids was found in the fraction of glycoprotein which remained undegraded after pepsin digestion. On the average, 10.2 mol of fatty acids/mg was substituted on this pepsin-resistant glycoprotein. After deacylation with hydroxylamine, the undegraded pepsinresistant glycoprotein became susceptible to proteolytic cleavage. The obtained results suggest that fatty acids covalently bound to gastric mucus glycoprotein are involved in the regulation of proteolytic digestion of mucus glycoprotein in the stomach.