一个双核Ni2金属中心在基架内的pH依赖的可逆形成
Brenna C Keegan1, Daniel Ocampo1, Jason Shearer1
1Department of Chemistry, Trinity University, 1 Trinity Place, San Antonio, TX 78212, U.S.A.
概括
这项研究详细介绍了一种含的,模仿超氧化物脱酶 (Ni2SODmds). 它与氧的反应性在较高的pH值下显著增加,这是由于硫联体的脱.
科学领域:
- 生物有机化学 生物有机化学
- 协调化学 协调化学
- 生物模拟化学 生物模拟化学
背景情况:
- 含的酶,如超氧化物脱酶 (Ni-SOD),在生物系统中起着至关重要的作用.
- 了解Ni-SOD模仿物的结构-活性关系对于开发新的催化剂和治疗剂至关重要.
研究的目的:
- 合成和表征一种含有两个Ni2+结合点的二硫化物桥接,模仿Ni-SOD.
- 为了研究Ni2 ((SODmds) 复合物的pH取决的结构和电子特性.
- 探索不同pH值的Ni2 ((SODmds) 复合物与分子氧的反应性.
主要方法:
- 一个具有Ni2+结合点的二硫化物桥接的合成.
- 射线吸收光谱 (SK边缘) 探测硫的协调和质子化状态.
- 电子结构计算以阐明反应机制.
主要成果:
- 在pH7.4时,该复合物以单核Ni(II) 位点的形式存在,具有质子化囊酸连接体.
- 在pH值9.6时,去质子化产生双核Ni2 (II) 复合体,由囊酸盐桥接.
- Ni2 ((SODmds) 复合体在pH值9.6时与pH值7.4.4相比,对O2的反应性增加.
- 电子结构计算显示,在pH值7.4时的硫质子化会使该复合物失活.
结论:
- 2 ((SODmds) 复合物的pH依赖性结构变化显著影响其与氧的反应性.
- 在生理pH下对硫联体的质子化会降低Ni-SOD模拟物的催化效率.
- 这项研究提供了对Ni-SOD机制和生物模拟催化剂设计的见解.
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