提取方法对米谷蛋白分子理化性质的影响

Effects of Extraction Methods on Physico-chemical Properties of Rice Glutelin

研究不同提取方法对米谷蛋白分子理化性质的影响,采用十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(sodium dodecyl sulfonate-polyacrylamide gel electrophoresis,SDS-PAGE)、体积排阻高效液相色谱(size exclusion chromatography-high-performance liquid chromatography,SEC-HPLC)、扫描电镜和差式扫描量热法对所提取的米谷蛋白分子的性质进行表征分析。结果表明:碱提法结合分步提取以及水洗工艺得到的米谷蛋白,蛋白含量达到(93.42±0.32)%;SDS-PAGE分析显示其主要有3条清晰条带(19、33、50 ku);SEC-HPLC检测到蛋白体系中的小分子部分和分子质量>106 u大分子部分较少;微观结构观察到其暴露出了蛋白质的骨架结构;同时这种方法所提取得的米谷蛋白焓值最高,热稳定性比较好。

The effects of different extraction methods on physico-chemical properties of rice glutelin were studied. Sodium dodecyl sulfonate-polyacrylamide gelelectrophoresis（SDS-PAGE）, size exclusion high performance liquid chromatography（SEC-HPLC）, scanning electron microscope（SEM） and differential scanning calorimetry（DSC） were used to characterize the properties of extracted proteins. The results showed that the protein content of rice glutelin prepared by alkali extraction combined with sequential extraction and washing process was（93.42±0.32）%. SDS-PAGE analysis revealed three clear bands（19, 33 ku and 50 ku）. The molecular weight distribution of the sample showed that there were fewer fractions with small molecules and large molecules larger than 106 u. Our microstructural observation demonstrated that the protein backbone structure was exposed after all four different alkali extractions. Meanwhile, the highest enthalpy of the sample showed its good thermal stability.