Effect of Gastrointestinal Protease Digestion on Bioactivity of Marine Peptides

Focus in nutritional science has turned towards components in, or added to, foods that may possess health beneficial activities beyond the classical nutritional value, namely functional food. Bioactive peptides are examples of such components. In vitro studies on bioactivities have mainly been executed without concerning subsequent digestion after intake and the aim of this work was hence to investigate how the in vitro antioxidative, antihypertensive and caspase activating activities of peptides are affected by digestion with gastrointestinal （GI） proteases. Five different fish protein hydrolysates were chosen to study the effect of in vitro digestion on bioactivity. The protein concentration decreased in all samples during digestion and the molecular weight distribution of the peptides shifted towards lower values. Thus, in vitro digestion with GI proteases resulted in a further degradation of the peptides obtained by hydrolysis. The antihypertensive effect increased in all samples after digestion with GI proteases whereas the antioxidative capacity decreased. The effect on the caspase activity depended on the proteases used in the preparation of hydrolysates. In conclusion, the caspase activity and antihypertensive activity are maintained during digestion with GI proteases, while the antioxidative capacity seems to be reduced.

鱼肌肉蛋白质组学分级过程的重现性研究

在比较蛋白质组学中,分级过程经常被用于去除高丰度蛋白质,从而提高低丰度蛋白质的浓度至检出限以上。作者为了证实在二维凝胶电泳分离流程中增加额外的分级过程将会减小对金头鲷宰前应激响应时间依赖检测中所引入的噪声和批次间的偏差,采用多维标度对结果数据进行了多参数分析。结果表明生物响应比分级引入的误差高出几个数量级,而批次间误差不小于不同IEF/SDS-PAGE运行所引入的偏差。