在M铁中铁氧酶位点的光谱定义:双核基质与辅因子活性位点的比较
Jennifer K Schwartz1, Xiaofeng S Liu, Takehiko Tosha
1Department of Chemistry, Stanford University, 333 Campus Drive, Stanford, California 94305, USA.
Journal of the American Chemical Society
|June 26, 2008
概括
马克西费里丁是必要的蛋白质纳米,用于储存铁. 这项研究揭示了青M铁素.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 生物物理学的生物物理.
背景情况:
- 马克西费里丁是24个子单元蛋白质纳米,对各种生物体的铁稳态至关重要.
- 铁以水合氧化铁的形式储存,防止自由基的破坏和病原体的利用.
- 铁的生物矿化在非海姆双铁基质活性部位被催化.
研究的目的:
- 为了研究M ferritin中的基质活性部位的Fe (II) 结合.
- 为了阐明双铁活性位点的结构和电子特性.
- 了解费里中铁吸收控制的机制.
主要方法:
- 循环二重化 (CD) 光谱学.循环二重化 (CD) 光谱学.
- 磁圆二极化 (MCD) 光谱法.磁圆二极化 (MCD) 光谱法.磁圆二极化 (MCD) 光谱法.
- 可变温度,可变场MCD (VTVH MCD) 用于探测Fe (II) 结合.
主要成果:
- 在活动地点确定了两个不等价的五坐标 (5C) 铁中心.
- 确定Fe (II) 中心之间的弱反铁磁合,由一个mu-1,3碳酸盐弥合.
- 观察到每个子单位内的活跃站点之间协调的Fe(II) 结合和合作.
- 描述了一个不寻常的活性位子连接体集,包括终端水分子.
结论:
- 青M铁素的活性部位结构不同于其他双铁酶.
- 协同结合和合作性表明一种调节费里铁负荷的机制.
- 独特的结构特征影响费里的催化和铁储存功能.
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