School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, China; Guangdong Food Green Processing and Nutrition Regulation Technologies Research Center, Guangzhou 510650, China.
School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, China; Guangdong Food Green Processing and Nutrition Regulation Technologies Research Center, Guangzhou 510650, China.
Food Chem. 2021 May 1;343:128555. doi: 10.1016/j.foodchem.2020.128555. Epub 2020 Nov 5.
Sodium dodecyl sulfonate polyacrylamide gel electrophoresis (SDS-PAGE), circular dichroism spectroscopy (CD), transmission electron microscope (TEM) and atomic force microscope (AFM) were used to analyze the structural properties and gastrointestinal digestive characteristics of natural insoluble undenatured type II collagen (IC II) and pepsin soluble undenatured type II collagen (SC II). Results showed that, after gastric digestion, especially under low pH conditions, some thick and short collagen fibers were dissolved from IC II, which was accompanied by the release of soluble protein with triple helix structure. As to SC II, when gastric digestion was performed under higher pH conditions, collagen fibers were mildly thinned and curved, and the triple helix structure was slightly destroyed. However, those changes hardly occurred during the intestinal digestion. Moreover, the undenatured type II collagen existing in SC II digestive supernatant was 1.2-12.4 times higher than that of IC II depending on the pH conditions. These results suggested that, it is more likely for SC II to exert its activity of relieving arthritis, and it should be taken when the pH of gastric environment is high.
十二烷基硫酸钠聚丙烯酰胺凝胶电泳（SDS-PAGE）、圆二色光谱（CD）、透射电子显微镜（TEM）和原子力显微镜（AFM）用于分析天然不溶性未变性 II 型胶原蛋白（IC II）和胃蛋白酶可溶性未变性 II 型胶原蛋白（SC II）的结构特性和胃肠道消化特性。结果表明，胃消化后，特别是在低 pH 条件下，IC II 中一些厚而短的胶原纤维溶解，同时释放出具有三螺旋结构的可溶性蛋白。对于 SC II，当在较高 pH 条件下进行胃消化时，胶原纤维轻度变细和弯曲，三螺旋结构略有破坏。然而，这些变化在肠道消化过程中几乎没有发生。此外，根据 pH 条件的不同，SC II 消化上清液中存在的未变性 II 型胶原蛋白是 IC II 的 1.2-12.4 倍。这些结果表明，SC II 更有可能发挥缓解关节炎的活性，并且应该在胃环境 pH 值较高时服用。
