玉米胚芽蛋白的分离及物化特性研究

Isolation and Characterization of Corn Germ Protein

摘要:

采用碱溶酸沉法提取玉米胚芽分离蛋白，利用氨基酸分析和电泳分析胚芽蛋白的氨基酸组成和有效亚基组成。凝胶层析分离玉米胚芽蛋白组分，并对各组分进行热变性温度及圆二色谱分析。氨基酸分析结果表明，玉米胚芽蛋白中谷氨酸和赖氨酸含量较高，其它氨基酸含量较均衡。还原的十二烷基硫酸钠-聚丙烯酰胺电泳（SDS-PAGE）图主要有九条谱带，其分子量依次为87.988、76.320、69.650、53.649、48.546、38.164、34.337、32.294和24.483 kDa。凝胶层析分离获得两个蛋白组分。差示扫描量热仪(DSC)分析表明分离所得两个组分的干粉变性温度分别为97.37 ℃和98.95 ℃，圆二色谱(CD)分析表明两个蛋白组分的二级结构主要为β-折叠和无规卷曲。

Abstract:

In this work, the isolation and characterization of corn germ protein extracting by traditional method was studied. The results showed an amino acid balance in the obtained protein except for Glu and Lys which showed high contents. SDS-PAGE analysis revealed that there were nine components in corn germ protein isolate with the molecular weight being of 87.988, 76.320, 69.650, 53.649, 48.546, 38.164, 34.337, 32.294 and 24.483 kDa, respectively. Two fractions separated from corn germ protein by gel filtration chromatography were obtained. Differential Scanning Calorimetry (DSC) analysis showed that the denaturation temperature of the obtained fractions were 97.37 and 98.95 ℃, respectively. The secondary structure analyed by (CD) revealed that the main conformation of the obtained fractions were β-sheet and random coil.