The carapace from the Chinese soft-shelled turtle (Pelodiscus sinensis) is used as a traditional Chinese medicine. Acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) from turtle carapace were isolated and characterized to screen novel collagen material in this study. Yields of 1.0% and 2.8% were obtained for ASC and PSC which contained glycine as the major amino acid and had high imino acid content. Both collagens had maximum ultraviolet absorption peaks of 220 nm. SDS-PAGE revealed that the structure of both collagens was similar, belonging to type I collagen. Relative viscosities of collagens were decreased as the temperature increased. Collagens showed minimum solubility at pH 8 and maximum solubility at a salt concentration of 3%. The denaturation temperature (Td) of PSC was higher whereas the melting temperature was lower than that of ASC. Both ASC and PSC appeared to be spongy like microstructure with fibrillar pores shown by scanning electron microscopy. The results suggest that collagens isolated from turtle carapace has high thermal stability with potential uses as new substitute for mammalian collagen in medicinal, food or biomaterial fields. However, their biological or pharmacological activities are needed to be further studied.

中华鳖 ( Pelodiscus sinensis)的甲壳) 用作中药。本研究从龟甲壳中分离并表征了酸溶性胶原蛋白 (ASC) 和胃蛋白酶可溶性胶原蛋白 (PSC)，以筛选新型胶原蛋白材料。以甘氨酸为主要氨基酸且亚氨基酸含量高的 ASC 和 PSC 的产率分别为 1.0% 和 2.8%。两种胶原蛋白的最大紫外线吸收峰为 220 nm。SDS-PAGE显示两种胶原蛋白结构相似，属于I型胶原蛋白。随着温度升高，胶原蛋白的相对粘度降低。胶原蛋白在 pH 值为 8 时显示出最小溶解度，在 3% 的盐浓度下显示出最大溶解度。PSC的变性温度（Td）高于ASC，而熔融温度低于ASC。扫描电子显微镜显示 ASC 和 PSC 均呈海绵状微结构，具有纤维状孔隙。结果表明，从龟甲壳中分离出的胶原蛋白具有很高的热稳定性，具有在医药、食品或生物材料领域作为哺乳动物胶原蛋白的新替代品的潜在用途。然而，它们的生物学或药理活性有待进一步研究。