玉米肽的酶法糖基化修饰及产物溶解性的研究

Enzymatic glycosylation of corn peptide and solubility of glycosylated product

以玉米醇溶蛋白为原料,先利用Alcalase碱性蛋白酶酶解制备玉米肽,再以转谷氨酰胺酶为催化剂,氨基葡萄糖为酰基受体,通过糖基化反应修饰玉米肽,以接糖量为指标,采用单因素实验和正交实验优化糖基化反应条件,并对修饰产物的溶解性进行研究。结果表明,氨基葡萄糖糖基化修饰玉米肽的最优条件为:反应初始pH 7.7,反应温度44℃,玉米肽质量分数3.5%,玉米肽与氨基葡萄糖质量比1∶3,酶添加量55 U/g(以玉米肽质量计),反应时间7 h。在最优条件下,接糖量为149.60 mg/g。与玉米肽相比,玉米糖肽的溶解性显著增加,尤其是pH 6.0时,玉米糖肽的溶解性增加16.31%。

With zein as raw material, the corn peptide was prepared by hydrolysis using Alcalase protease, and modified by enzymatic glycosylation with transglutaminase as catalyst and glucosamine as acyl acceptor.The amount of glucosamine conjugated onto corn peptide was used as index, and single factor experiment and orthogonal experiment were used to optimize the glycosylation reaction conditions.Meanwhile, the solubility of corn peptide modified by glycosylation was studied. The results showed that the optimal conditions were obtained as follows: initial reaction pH 7.7, reaction temperature 44℃, mass fraction of corn peptide 3.5%, mass ratio of corn peptide to glucosamine 1∶3, enzyme dosage 55 U/g(based on the mass of corn peptide), and reaction time 7 h.Under the optimal reaction conditions, 149.60 mg/g of glucosamine was covalently conjugated onto corn peptide.Compared with corn peptide, the solubility of corn glycopeptide significantly increased, especially at pH 6.0, the solubility of corn glycopeptides increased by 16.31%.