摘要
利用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳、扫描电子显微镜、差示扫描量热法以及傅里叶红外光谱(Fourier transform infrared spectrometer,FTIR)对小米中4 种蛋白组分进行结构特性分析。研究表明,醇溶蛋白是由低分子质量亚基(11~25 kDa)构成,而清蛋白、球蛋白和谷蛋白亚基分布较广(11~180 kDa),其中清蛋白所含亚基数目最多,醇溶蛋白、清蛋白以及球蛋白分子之间连接紧密,以聚集状态存在,而谷蛋白分子连接松散,表面光滑。球蛋白在71.33 ℃条件下发生变性;醇溶蛋白的变性温度最高,达到110.67 ℃。FTIR研究表明,醇溶蛋白、谷蛋白和球蛋白的二级结构主要由β-折叠构成,其含量分别为37.72%、43.39%、42.23%;β-转角以及β-反平行折叠结构含量最丰富的是醇溶蛋白,分别为16.64%和12.73%。4 种蛋白组分结构含量差异显著(P<0.05)。
The structures of 4 protein components in millet were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), scanning electron microscopy, differential scanning calorimetry and Fourier transform infrared spectroscopy (FTIR). This study showed that millet gliadin was composed of low-molecular-mass subunits (11 25 kDa), while albumin, globulin and glutenin subunits were widely distributed (11 180 kDa). Albumin contained the largest number of subunits. The prolamin, albumin and globulin molecules were closely linked and existed in an aggregated state, while the gluten molecules were loosely connected and had a smooth surface. The globulin was denatured at 71.33 ℃, and the prolamin had the highest denaturation temperature of 110.67 ℃. FTIR study showed that the secondary structures of the prolamin, gluten and globulin were mainly composed of β-sheet, accounting for 37.72%, 43.39%、42.23% of the total amount, respectively. The prolamin contained the most abundant structures of β-turn and antiparallel β-sheet, accounting for 16.64% and 12.73% of the total amount, respectively. However, the secondary structure contents of the four protein components were significantly different (P < 0.05).
作者
郭莲东
徐丽
欧才智
丁阳月
张高鹏
倪春蕾
程建军
GUO Liandong;XU Li;OU Caizhi;DING Yangyue;ZHANG Gaopeng;NI Chunlei;CHENG Jianjun(College of Food Science,Northeast Agricultural University,Harbin 150030,China)
出处
《食品科学》
EI
CAS
CSCD
北大核心
2019年第24期201-206,共6页
Food Science
基金
“十三五”国家重点研发计划重点专项（2017YFD0401200）
关键词
小米
蛋白组分
亚基
二级结构
millet
protein components
subunit
secondary structure
