4-10 Agriculture Forestry Centre, Department of Agricultural and Food Nutritional Science, University of Alberta, Edmonton, Alberta, Canada T6G 2P5.
J Agric Food Chem. 2010 Jul 14;58(13):7664-72. doi: 10.1021/jf101323y.
Ovotransferrin is a glycoprotein well-known for its iron-binding property. Ovotransferrin was reported to have antioxidative properties, but the presence of antioxidant peptides within the protein has not been reported. The purpose of the study was to characterize the antioxidant peptides within ovotransferrin. Ovotransferrin was sonicated and hydrolyzed by thermolysin, and peptides from the hydrolysate were fractionated by ion-exchange fast protein liquid chromatography and reversed-phase high-performance liquid chromatography. Fourteen peptides derived from ovotransferrin were characterized using LC-MS/MS, and their oxygen radical absorbance capacity (ORAC) values were determined using synthetic peptides. Two tetrapeptides (Trp-Asn-Ile-Pro and Gly-Trp-Asn-Ile) showed the highest antioxidant activity. Interestingly, the addition of amino acid residues to either the N or C terminus of the two peptides decreased the antioxidant activity, suggesting that the motif of Trp-Asn-Ile is responsible for the high antioxidant activity.
卵转铁蛋白是一种众所周知的具有铁结合特性的糖蛋白。据报道，卵转铁蛋白具有抗氧化特性，但蛋白质中是否存在抗氧化肽尚未报道。本研究的目的是研究卵转铁蛋白中的抗氧化肽。卵转铁蛋白经超声处理和胰凝乳蛋白酶水解，水解产物的肽段经离子交换快速蛋白液相色谱和反相高效液相色谱分离。利用 LC-MS/MS 对 14 个源自卵转铁蛋白的肽段进行了鉴定，并使用合成肽测定了它们的氧自由基吸收能力（ORAC）值。两种四肽（色氨酸-天冬酰胺-异亮氨酸-脯氨酸和甘氨酸-色氨酸-天冬酰胺-异亮氨酸）表现出最高的抗氧化活性。有趣的是，向两种肽的 N 或 C 末端添加氨基酸残基会降低抗氧化活性，表明色氨酸-天冬酰胺-异亮氨酸的基序是高抗氧化活性的原因。
