小麦胚芽蛋白钙络合物的制备及结构表征

The preparation of complex with wheat germ protein hydrolyzates binding to calcium

以小麦胚芽蛋白为原料，经蛋白酶酶解后与Ca^2＋键合形成肽钙络合物，可作为第4代钙补充剂。碱性蛋白酶具有更高的麦胚蛋白水解活性，是制备高键合钙能力水解液的最适合酶类，且水解度在21．5％时钙的结合量达最大值18mg／g蛋白；SDS-PAGE表明碱性蛋白酶迅速降解麦胚蛋白中高分子量亚基，且50kDa和32-34kDa亚基的水解与钙离子键合能力密切相关；键合钙能力强的水解产物中主要含Glu、Arg、Asp、Gly，且含44％疏水性氨基酸；分子量分布显示键合钙的小肽分子量在2000Da以下；全波长扫描和红外图谱表明肽段上的氨基和羧基均参与了键合反应，并生成了新的物质——麦胚肽钙络合物。

In this paper, wheat germ protein （WGP） as raw material was hydrolyzed by protease and bond to Ca^2＋. The formation of wheat germ peptide-calcium complex can be the fourth-generation calcium supplements. Alcalase could hydrolyze wheat germ protein more easily. The combined amount of calcium reached a highest value of 18mg/g protein at the degree of hydrolysis of 21.5%. Result of SDS-PAGE showed the quick degradation of the high molecular weight subunit in WGP, and showed that the hydrolysis of 50kDa and 32 - 34 kDa subunit was intimately related to calcium binding capacity. The hydrolysates with high calcium binding ability mainly contained Glu, Arg, Asp, Gly and 44% of hydrophobic amino acids, in which the molecular weight distribution was lower than 2 000Da. Results of full wavelength scanning and infared spectra revealed that the amino and carboxyl groups were involved in the binding reaction and generated new material-wheat germ peptide-calcium complex.