Zhongguo youzhi (Sep 2024)
TGase催化的壳寡糖糖基化修饰玉米肽的抗氧化活性Antioxidant activity of zein peptides modified by TGase-catalyzed chitosan oligosaccharides glycosylation
Abstract
为进一步提高玉米肽的抗氧化活性，以玉米醇溶蛋白源活性肽为原料，利用谷氨酰胺转氨酶（TGase）催化壳寡糖（分子质量1 500 Da）与玉米肽共价结合制备玉米糖肽，研究壳寡糖的糖基化修饰对玉米肽抗氧化活性的影响，并对玉米糖肽进行体外模拟胃肠消化，表征玉米糖肽在体内发挥抗氧化活性的潜力。结果表明：TGase催化的壳寡糖共价结合使玉米肽的肽含量和体外消化率显著提高；在质量浓度为2.0 mg/mL时，TGase催化壳寡糖糖基化修饰使玉米肽的DPPH自由基、羟自由基、超氧阴离子自由基清除率，Fe2+螯合率和还原力提高，体外消化使玉米糖肽的DPPH自由基、羟自由基清除率和还原力提高，而Fe2+螯合率和超氧阴离子自由基清除率降低。综上，TGase途径的壳寡糖糖基化反应使玉米肽的抗氧化活性显著提高，且体外消化可以促进玉米糖肽抗氧化活性的释放(Fe2+螯合能力和超氧阴离子自由基清除能力除外)。To further enhance the antioxidant activity of the zein peptides, the active peptides from zein have been used as raw material, and then zein glycopeptides were prepared by transglutaminase(TGase)-induced chitosan oligosaccharides (molecular weight 1 500 Da) covalent binding onto zein peptides. The effect of chitosan oligosaccharides modification on the antioxidant activities of zein peptides was studied. In addition, zein glycopeptides were simulated by gastrointestinal digestion in vitro to characterize its antioxidant potential in vivo. The results showed that the covalent binding of chitosan oligosaccharides catalyzed by TGase significantly increased peptide content and in vitro digestibility of zein peptides. At the mass concentration of 2.0 mg/mL, the DPPH, hydroxyl and superoxide anion radicals scavenging rates, Fe2+-chelating capacity and reducing capacity of TGase modified zein peptides increased, also the DPPH, hydroxyl radicals scavenging rates and reducing capacity of zein glycopeptides after in vitro digestion increased, while the Fe2+-chelating capacity and the superoxide anion radical scavenging rate decreased. In conclusion, TGase-modiated chitosan glycosylation significantly improves the antioxidant activities of zein peptides, and in vitro digestion can promote the release of the antioxidant activities of zein glycopeptides (except Fe2+-chelating capacity and superoxide anion radical scavenging ability).
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