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| D-氨基半乳糖修饰对玉米醇溶蛋白结构性质及生物活性的影响 |
| Effects of D-galactosamine modification on structural properties and biological activities of zein |
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| DOI： |
| 中文关键词: 玉米醇溶蛋白 D-氨基半乳糖 糖基化 结构性质 抗氧化活性 |
| 英文关键词:zein D-galactosamine glycosylation structural property antioxidant activity |
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| 中文摘要: |
| 以含有伯胺基团的D-氨基半乳糖为酰基受体，通过谷氨酰胺转氨酶（TGase）催化的糖基化反应修饰玉米醇溶蛋白，分析了糖基化修饰对玉米醇溶蛋白结构性质及生物活性的影响。红外光谱的测定结果表明，在TGase的催化下，玉米醇溶蛋白与D-氨基半乳糖发生了共价结合。在D-氨基半乳糖不存在的反应体系，TGase催化的玉米醇溶蛋白分子间的交联反应发生的概率低，对玉米醇溶蛋白结构性质的影响较小。与玉米醇溶蛋白相比，D-氨基半乳糖的共价结合使玉米醇溶蛋白的游离巯基含量降低67.45 μmol/g，变性温度和总变性焓分别增加8.8?℃和31.97 J/g，即糖基化增加了玉米醇溶蛋白的热稳定性。糖基化修饰使玉米醇溶蛋白的抗氧化活性（包括DPPH自由基、超氧阴离子自由基和羟自由基清除活性和还原力）和乙醇脱氢酶激活率均显著提高，为进一步研究糖基化玉米醇溶蛋白的护肝活性奠定了理论基础。 |
| 英文摘要: |
| With D-galactosamine containing primary amino groups as an acyl acceptor, zein was modified by glycosylation reaction catalyzed by transglutaminase(TGase). The effects of glycosylation modification on the structural properties and biological activities of zein were evaluated. The result of Fourier transform infrared spectra indicated that D-galactosamine covalently conjugated to the zein catalyzed by TGase. In the reaction system without D-galactosamine, the probability of cross-linked reaction of zein molecules catalyzed by TGase was low, and the cross-linked reaction had little effect on the structural properties of zein. Compared with original zein, the free sulfhydryl groups of the glycosylated zein decreased by 67.45 μmol/g, the denaturation temperature and the total denaturation enthalpy of the glycosylated zein increased by 8.8?℃ and 3197 J/g, respectively. These indicated that the thermal stability of zein was significantly improved by glycosylation. Meanwhile, antioxidant activities(including DPPH, superoxide anion, hydroxyl radical scavenging activities and reducing power) and alcohol dehydrogenase activation rate of the glycosylated zein increased significantly, which laid the theoretical foundation for further study on the hepatoprotective effects of the glycosylated zein. |
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