School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, PR China.
Food Chem. 2013 Nov 15;141(2):1287-94. doi: 10.1016/j.foodchem.2013.03.088. Epub 2013 Apr 12.
Proteolysis of noncollagenous proteins in sea cucumber, Stichopus Japonicus, body wall (sjBW) was investigated. The proteins removed from sjBW by SDS and urea extraction were mainly noncollagenous proteins with molecular weights about 200kDa (Band I) and 44kDa (Band II), respectively. Band I and Band II were identified as major yolk protein (MYP) and actin, respectively, from holothurian species by liquid chromatography-mass spectrometry (LC-MS/MS) with significant scores. Based on TCA-soluble oligopeptide assay, the optimum proteolysis condition of noncollagenous proteins was at 46.3°C and pH 6.1, by response surface methodology. The proteolysis of MYP, and actin, was partially inhibited by cysteine protease inhibitors, including Trans-epoxysuccinyl-l-leucyl-amido (4-guanidino) butane (E-64), iodoacetic acid, antipain and whey protein concentrate. These results suggest that cysteine proteases are partially involved in the proteolysis of noncollagenous proteins in body wall of sea cucumber, S. japonicus.
本研究探讨了海参体壁中非胶原蛋白的蛋白水解作用。SDS 和尿素提取去除的蛋白质主要是非胶原蛋白，分子量分别约为 200kDa（Band I）和 44kDa（Band II）。通过液相色谱-质谱联用（LC-MS/MS）分析，Band I 和 Band II 分别被鉴定为来自棘皮动物的主要卵黄蛋白（MYP）和肌动蛋白，得分显著。基于三氯乙酸可溶性寡肽测定，通过响应面法确定非胶原蛋白的最佳蛋白水解条件为 46.3°C 和 pH 6.1。半胱氨酸蛋白酶抑制剂，包括反式-环氧琥珀酰基-L-亮氨酰-酰胺（4-胍基）丁烷（E-64）、碘乙酸、抑蛋白酶肽和乳清蛋白浓缩物，部分抑制了 MYP 和肌动蛋白的蛋白水解。这些结果表明，半胱氨酸蛋白酶部分参与了海参体壁中非胶原蛋白的蛋白水解。
