Biological activity and mechanisms of peptides derived from oat proteins

人体维持氧化还原平衡的能力在过量氧化剂分子存在的情况下会受到影响。当食用氧化食品时，在感染或接触过渡金属期间，所有这些都会增加活性氧物种(即自由基)的产生，都可能发生这种情况。这种氧化还原失衡与包括癌症、心血管疾病和黄斑变性在内的几种慢性疾病的病因有关。具有抗氧化活性的化合物可以防止食物的氧化变质，还可以减少与上述慢性病相关的风险因素。尽管谷物的消费与一些与年龄有关的疾病的发病率下降有关，但造成观察到的影响的食物成分的性质及其作用机制并未得到很好的定义。本研究的目的是鉴定谷物中的生物活性多肽，并在细胞水平上确定它们的作用机制，以阐明有助于疾病预防的活性成分。燕麦种子用于纤维提取的利用率增加，会留下约50%的高蛋白残留物，这些残留物将被用作新生物活性多肽的来源，以防止食品变质，减少氧化应激，最终改善加拿大人的健康。该方法将包括蛋白质的最佳提取和随后的酶消化；多肽的分离和鉴定；以及对活性负责的化学描述符的确定。它还将确定多肽的定位以及它们与细胞模型中的磷脂和多肽代谢物的相互作用。在食品系统中使用多肽作为抗氧化物质的优势包括其额外的营养功能。这些结果将导致建立模型来研究食源性多肽的抗氧化特性，并更好地理解它们在调节/预防人类慢性疾病中的作用。它还将提高燕麦种子的附加值利用，为加拿大经济带来显著的经济效益。

The ability of the human body to maintain a redox balance is compromised in the presence of excess oxidant molecules. This can occur when oxidized foods is consumed, during infection or exposure to transition metals all of which, increased the production of reactive oxygen species (i.e. free radicals). This redox imbalance is involved in the etiology of several chronic diseases including cancer, cardiovascular diseases and macular degeneration. Compounds that have antioxidant activities can prevent oxidative deterioration of foods and also reduce the risk factors associated with the above chronic ailments. Although, the consumption of cereals is correlated with a decreased incidence of some of age-related diseases, the nature of food ingredients responsible for the observed effects and their mechanisms of action are not well defined. The aim of this research is to identify bioactive peptides in grains and to determine their mechanism of action at the cellular level in order to elucidate the active elements that contribute to disease prevention. Increased utilization of oat seeds for fibres extraction leaves behind a high protein residue about 50% by weight that will be used as sources of new bioactive peptides to prevent the deterioration of foods, to reduce oxidative stress and ultimately improve Canadians' health. The approach will include optimum extraction of proteins and subsequent enzymatic digestion; separations and identification of peptides; and the determination of chemical descriptors responsible for activities. It will also determine the localization of peptides and their interaction with phospholipids in cellular models as well as peptide metabolites. Advantages of using peptides as antioxidant substances in food systems include their additional nutritional functions. The results will lead to a development of model to study the antioxidant properties of food-derived peptides, and to a better understanding of their role in the regulation/prevention of chronic human diseases. It will also enhance value-added utilization of oat seeds with significant economic benefits to the Canadian economy.