超声预处理对麦胚蛋白结构的影响  

Effect of Ultrasonic Pretreatment on the Structure of Wheat Germ Protein

作　　者：颜辉[1] 张琦[1] 聂旭东[2] 朱胜虎[2] 余永建[2] 熊孟[1] 江明珠[1] 

机构地区：[1]江苏科技大学生物技术学院,江苏镇江212018 [2]江苏恒顺集团有限公司,江苏镇江212028

出　　处：《食品与机械》2017年第4期13-17,共5页Food and Machinery

基　　金：镇江市重点研发计划--产业前瞻与共性关键技术(编号:GY2015006)

摘　　要：采用超声波对麦胚蛋白进行不同时间的预处理,并利用荧光、拉曼光谱分析溶液中蛋白的结构,红外光谱分析冻干后蛋白结构。结果显示,超声预处理会影响酶解法制备降血糖肽的活性,30min时活性最高。荧光光谱分析提示超声预处理能够引起麦胚蛋白中色氨酸残基由疏水区向亲水区转移,但蛋白结构未发生重大破坏。拉曼光谱分析超声预处理30min时对蛋白结构的影响最大,β-折叠含量降低最多。红外光谱分析显示蛋白结构随时间变化,在35 min时变化最大,α-螺旋含量显著降低,无规则卷曲含量显著升高。拉曼和红外光谱提供的信息比荧光丰富,拉曼光谱能够提供更准确的水溶液酶催化体系中的底物结构,对于蛋白的酶解反应更有指导意义。Ultrasound pretreatment of wheat germ protein can increase the activity of hypoglycemic peptides prepared from enzymatic hydrolysis, and it is of great theoretical and practical sig- nificance to clarify the effect of ultrasonic wave on the structure of wheat germ protein. In this study, wheat germ protein was pretreated by ultrasonic wave with different time, and the structure of the protein was analyzed by fluorescence and Raman spectroscopy, and then the slructure of lyophilized protein was analyzed by IR spec- troscopy. The results showed that ultrasonic pretreatment influenced the enzymatic hydrolysis of hypoglycemic peptides, and the activity raised to the highest at 30 min. The fluorescence spectroscopy indiea-ted that the pretreatment could induce the transferring of tryptophan residues from hydrophobic to hydrophilic regions in wheat germ pro- tein. However, the protein structure was not found significant dam- age. Raman spectroscopy showed that protein structure was strongly affected at 30 min, and the content of β-sheet decreased to the lowest. Infrared spectroscopy analysis showed that protein structure changed with time, and the maximum change was at 35 rain. Moreo- ver, the a-helix content decreased significantly, while the random- coil content increased significantly. Raman spectroscopy and infrared spectroscopy provided more information than the fluorescence. Raman spectroscopy provided more accurate substrate structure in water-soluble enzyme catalytic system, and this showed more in- structive for the protein enzymatic reactions.

关 键 词：超声预处理 麦胚蛋白 降血糖肽 荧光光谱 拉曼光谱 红外光谱 

分 类 号：TS201.21[轻工技术与工程—食品科学]