小米谷蛋白及醇溶蛋白结构特征

采用碱提酸沉法提取小米谷蛋白,乙醇浸提小米醇溶蛋白,对2种蛋白的结构特征进行研究。结果表明,小米醇溶蛋白的组成较为简单,且分子量较小,而小米谷蛋白在高分子量和低分子量都有分布。XRD分析发现二者皆为无定型结构。圆二色光谱测定结果表明,小米醇溶蛋白属于全α型结构,有序性优于小米谷蛋白。另外,通过原子力显微镜观测发现,小米醇溶蛋白呈球状结构,分散状态,而小米谷蛋白分布较为密集。

Structural characteristics of millet glutenin and gliadin

Millet glutenin and gliadin was obtained by alkali extraction and acid precipitation and millet gliadin was distracted by ethanol. Then their structural characteristics were analyzed. SDS-PAGE electrophoresis results showed that the molecular weight of the millet gliadin was small, while millet glutenin was distributed from high molecular weight to low molecular weight. Furthermore, the XRD analysis showed that both the two kinds of proteins were amorphous structures. The secondary structure was measured by circular dichroism. Millet gliadin belonged to all alpha structure, and its order was better than that of millet alkali soluble protein. Moreover, by atomic force microscopy analysis, millet gliadin was spherical and its distribution was rather dispersed. In contrast, the distribution of millet glutenin was more concentrated.