硒调控糙米谷蛋白结构和功能特性的机制研究

Regulation of Selenium on the Structural and Functional Properties of Brown Rice Glutenin

以天然高硒糙米与低硒糙米为原料,采用分级提取法提取糙米蛋白并对其进行结构表征,通过生物信息学技术结合蛋白组学技术探究蛋白的生物学意义。结果表明:高硒糙米和低硒糙米4种蛋白(清蛋白、球蛋白、醇溶蛋白和谷蛋白)中谷蛋白的蛋白质含量(86.39%)以及硒含量(363.80μg/100 g)最高;与低硒谷蛋白相比,高硒谷蛋白没有产生新的化学键,但其α-螺旋含量减少,无规则卷曲含量增多,蛋氨酸和游离巯基含量降低。Protein Ontology(GO)功能注释表明2种蛋白在生物过程、细胞成分及分子功能中,蛋白数最多的二级功能相同;与低硒谷蛋白不同的是,高硒谷蛋白Kyoto Encyclopedia of Proteins and Genomes(KEGG)通路注释具有环境信息处理通路。硒强化使糙米谷蛋白提取物中蛋白质含量、硒含量增加,谷蛋白结构发生了一定的变化,高硒谷蛋白与低硒谷蛋白其潜在的功能有一定差异。

Two kinds of natural selenium-enriched brown rice with different selenium content were used as raw materials,brown rice proteins were extracted by Osborne classification method.The protein structure was characterized.Bioinformatics and proteomics were used to explore the biological significance of proteins.The results showed that the content of glutenin protein(86.39%)and selenium(363.80μg/100g)in high selenium brown rice and low selenium brown rice(albumin,globulin,gliadin and glutenin)was the highest.Compared with low selenium glutenin,high selenium glutenin did not produce new chemical bond,but itsα-helix content decreased,random coil content increased.Besides,methionine and free sulfhydryl content decreased in high selenium glutenin.The functional annotation of Protein Ontology(GO)showed that the secondary functions of the two proteins with the largest number of proteins were the same in biological processes,cellular components and molecular functions.The annotation of KEGG pathway showed that high selenium glutenin had environmental information processing pathway compared with low selenium glutenin.The content of protein and selenium in brown rice glutenin extract increased with selenium biofortification,the structure and function of glutenin changed to some extent.