圆二色光谱法研究环境因素对细胞红蛋白二级结构的影响  

Circular Dichroism Spectral Studies on Effect of Environmental Factors on Secondary Structure of Cytoglobin

作　　者：田素燕[1] 李连之[1] 高磊[1] 穆建帅[1] 刘晓燕[1] 谭相石[1] 

机构地区：[1]聊城大学化学化工学院,聊城252059

出　　处：《分析化学》2009年第8期1097-1101,共5页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金(No.20471025)资助项目

摘　　要：采用远紫外圆二色光谱法系统地研究了细胞红蛋白(cytoglobin,Cygb)的浓度、环境温度、溶液的pH值和溶剂性质对细胞红蛋白二级结构的影响。结果表明:当Cygb浓度<1μmol/L时,它主要以α-螺旋形式存在,其α-螺旋含量>60%;当Cygb浓度从0.3μmol/L增大到2.0μmol/L时,其α-螺旋含量迅速降低;当Cygb浓度>2.0μmol/L时,其α-螺旋含量随浓度的增大变化很小(约30%)。随着温度的升高,Cygb的α-螺旋含量逐渐减小,但既使温度达到368K,它仍保持有20%的α-螺旋结构,说明该蛋白具有较高的热稳定性。在弱酸性和弱碱性溶液中,Cygb的二级结构都会有不同程度的破坏。在甲醇和乙醇中,Cygb的α-螺旋含量明显增加,这说明醇类可以诱导其α-螺旋的生成。The effects of concentration of cytoglobin （Cygb） protein, temperature, pH value of solution and solvent on the secondary structure of Cygb were investigated by far-UV circular dichroism （CD） spectroscopy. The results show that Cygb mainly exists in a-helix form when its concentration is lower than 1 retool/L, wherein contains more than 60% a-helices. However, its α-helix content rapidly decreases with the concentration increases from 0. 3 mmol/L to 2.0 mmol/L and remains almost unchanged when its concentration is higher than 2. 0 mmol/L, wherein contains about 30% α-helices. The α-helix content of Cygb decreases with increasing temperature, but over 20% of helices can be kept at 368 K, which indicates that Cygb is a protein with high thermal stability. Cygb loses its α-helical secondary structure in either acidic or alkaline solution to some extent. The α-helix content of Cygb in methanol and ethanol is obviously higher than that in water. Therefore, methanol and ethanol can induce the formation of α-helix structure of Cygb.

关 键 词：细胞红蛋白 圆二色光谱 二级结构 Α-螺旋 

分 类 号：Q51[生物学—生物化学]