中心蛋白C端半分子与Sm^(3+)作用的光谱研究  

Spectra of Binding of Sm^(3+) with C-Terminal Domain of Euplotes Octocarinatus Centrin

作　　者：贾承政[1] 赵亚琴[1] 杨斌盛[1] 

机构地区：[1]山西大学分子科学研究所化学生物学与分子工程教育部重点实验室,山西太原030006

出　　处：《中国稀土学报》2013年第3期338-343,共6页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金(20901048;20771068);山西省自然科学基金(2011021006-1);山西省留学归国基金(201013);教育部博士点专项基金(20091401110007)资助

摘　　要：在0.01 mol.L-1Hepes,0.15 mol.L-1NaCl,pH 7.4及室温条件下,通过荧光光谱、圆二色光谱和紫外差光谱的方法研究了Sm3+与八肋游仆虫中心蛋白C端半分子(C-terminal domain of Euplotes octocarinatus centrin,C-EoCen)III,IV结合位点的结合能力及结合后对蛋白质构象的影响。结果表明,Sm3+与C-EoCen结合后,蛋白质从关闭式构象转变为开放式构象,蛋白的疏水性结构域外露程度增强,同时蛋白的α-螺旋含量明显增大;Sm3+与C-EoCen的III,IV结合位点的条件稳定常数分别为:lgKIII=6.23±0.39,lgKIV=6.81±0.51。The binding of Sm3＋ with the C-terminal domain of Euplotes octocarinatus centrin （ C-EoCen ） were investigated by fluorescence spectra, circular di- chroism spectroscopy and difference UV-Vis spectra in 0.01 mol-L-I Hepes, 0.15 mol·L-1 NaC1 at pH 7.4 and room temperature. The Sm3 ＋ binding with C-Eo- Cen resulted in the conformation change of C-EoCen from closed state to open state and was accompanied by enhancement of the exposed hydrophobic surfaces. In addition, the cx-helix content of C-EoCen was in- creased by virtue of addition of Sm3 ＋. By introducing competitive ligand xylenol orange, the conditional binding constants of site HI and IV on C-EoCen with Sm3 ＋ were calculated to be lgKⅢ = 6.23 ± 0.39 and lgKⅣ =6.81 ±O. 51, respectively.

关 键 词：Sm3+ 中心蛋白 构象变化 光谱 

分 类 号：O614.33[理学—无机化学] O641.4[理学—化学]