摘要
利用荧光滴定法研究了9种金属离子与序列特异性的DNA结合结构域(p53DBD)的结合反应,其结合能力依次为Fe3+>Zn2+>Cu2+>Ca2+>Mg2+>Ba2+>Mn2+>Ni2+>Co2+。圆二色谱研究结果表明,Ba2+,Ca2+,Co2+,Mn2+及Ni2+并未引起蛋白二级结构变化;Zn2+,Mg2+及Fe3+诱导蛋白结构细微调整;而Cu2+结合导致蛋白螺旋结构大量丢失。ANS结合研究结果表明,Mg2+与Zn2+相似,诱导p53DBD蛋白表面疏水性增强,而Fe3+引起p53DBD蛋白表面疏水性降低。因此,Mg2+和Fe3+可能是影响或调节p53活性的潜在因子之一。
Site-specific recognition and DNA-binding activity of tumor suppressor protein （ p53 ） are crucial for its tumor suppressor function. Previous reports have shown that metal ions could affect specific recognition and DNA-binding activity of p53 DNA binding domain （DBD）. In this study, the binding reaction between p53DBD and nine kinds of metal ions was investigated by fluorescence titration method; the binding affinity of metal ions to p53DBD is Fe^3＋ 〉Zn^2＋ 〉 Cu^2＋ 〉 Ca^2＋ 〉 Mg^2＋ 〉 Ba^2＋ 〉 Mn^2＋ 〉 Ni^2＋ 〉 Co^2＋. The analysis of the far-UV CD data clearly suggested that the binding of Ba^2＋ , Ca^2＋ , Co^2＋ , Mn^2＋ and Ni^2＋ did not induce the changes in protein secondary structure. The binding of Zn^2＋ , Mg^2＋ and Fe^3＋ induced a subtle conformational change, while the binding of Cu^2 ＋ resulted in a lot of loss in its helical content. The analysis of 8-anili- no-l-naphthalenesulfonic acid （ANS） binding data showed that the binding of Mg^2＋ enhanced hydrophobic exposure on protein surface like Zn^2＋, while Fe^3＋ decreased hydrophobic exposure. Therefore, Mg^2＋ and Fe^3 ＋ may be one of potential factors to affect or regulate the transactivation of p53.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2009年第8期1131-1136,共6页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金(No.90403140)资助项目
关键词
金属离子
蛋白结构
亲和性
疏水性
荧光光谱
Metal ions, protein structure, affinity, hydrophobic, fluorescence spectrum
