红外光谱法研究铬对酵母细胞内蛋白二级结构的影响  

EFFECT OF Cr ON SECONDARY STRUCTURE OF YEAST PROTEIN WITH FT-IR

作　　者：刘鹭[1] 侯东军[2] 陈锋亮[1,3] 吕加平[1] 

机构地区：[1]中国农业科学院农产品加工研究所/农业部农产品加工与质量控制重点开放实验室,北京100193 [2]中国动物疫病预防控制中心,北京100125 [3]山东省农业科学院农产品研究所,山东济南250100

出　　处：《核农学报》2012年第3期505-510,共6页Journal of Nuclear Agricultural Sciences

基　　金：国家航天育种工程项目(2006HT20013);中央级公益性科研院所基本科研业务费专项(0032012019)

摘　　要：利用氨水、Sephadex G-75对富铬酵母、空白酵母进行蛋白提取,采用红外光谱测定及数学方法对比分析铬作用前后蛋白质二级结构的变化,探讨铬对蛋白结构的影响。结果显示,铬与蛋白的键合导致大分子蛋白中的α-螺旋结构和无规则卷曲结构被破坏,α-螺旋结构由11.35%降至1.63%,无规则卷曲结构略有下降,β-转角结构增加,由33.88%升至52.72%,β-折叠结构几乎无变化;小分子蛋白的β-折叠结构被破坏,由61.41%降至48.54%,无规则卷曲和α-螺旋结构比例增加,由1.41%增加至13.30%,α-螺旋结构略有增加,β-转角结构几乎无变化。与铬结合的大分子蛋白中,β-转角结构占优势;与铬结合的小分子蛋白中,β-折叠结构占优势。Chromium-binding substance was isolated by ammonia extract and gel filtration chromatography.The secondary structure of chromium-binding substance was determined and analyzed by FT-IR combined with deconvolution,second derivative spectrum and curve fitting.The combination of chromium and protein in vivo resulted into the changes of the secondary structure.As to the high-molecular weight chromium-binding substance,the percentage of α-helix decreased from 11.35% to 1.63% and the percentage of random coil decreased a little.The percentage of β-turn increased from 33.88% to 52.72%,but which of β-sheet did not change.With regard to the low-molecular weight chromium-binding substance,the percentage of β-sheet decreased from 61.41% to 48.54%.The percentage of random coil increased from 1.41% to 13.30% and that of α-helix increased a little.The percentage of β-turn did not change.The major secondary structure of the high-molecular weight chromium-binding substance was β-turn;the major secondary structure of the low-molecular weight chromium-binding substance was β-sheet.

关 键 词：红外光谱 铬 二级结构 葡萄糖耐量因子 酵母 

分 类 号：Q51[生物学—生物化学] O657.33[理学—分析化学]