通过新的S-甲氨酸相互作用,PcoC的抗铜蛋白协调Cu(I)
Katrina Peariso1, David L Huffman, James E Penner-Hahn
1Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA.
Journal of the American Chemical Society
|January 9, 2003
概括
大肠杆菌的抗铜蛋白PcoC结合铜和其他金属. 它独特的结构揭示了一个新的富含 metionin 的铜结合部位,这对于在铜压力下细菌生存至关重要.
科学领域:
- 生物化学 生物化学
- 金属蛋白的化学成分
- 微生物耐药性的机制
背景情况:
- 大肠杆菌的抗铜蛋白PcoC在高铜压力下对细菌的生存至关重要.
- PcoC具有独特的富含 metionin 的序列,暗示 metionin 在铜结合中的非传统作用.
- 之前的研究表明,β-barrel折叠类似于蓝铜蛋白.
研究的目的:
- 研究大肠杆菌PcoC蛋白质的金属结合特性和结构特征.
- 阐明PcoC蛋白中铜的协调化学反应,特别是氨酸残留物的作用.
- 了解PcoC的减少 (Cu(I)) 和氧化 (Cu(II)) 形式之间的结构差异.
主要方法:
- 射线吸收光谱 (XAS) 用于分析铜位结构在两个氧化状态.
- 对阿波蛋白的结晶学研究.
- 金属结合试验以确定PcoC对Cu (I),Cu (II),Hg (II) 和Ag (I) 的亲和力.
主要成果:
- PcoC既结合了Cu (I) 和Cu (II),也结合了Hg (II) 和Ag (I).
- 在PcoC中的Cu (II) 和Cu (I) 位点之间存在显著的结构差异,与典型的蓝铜蛋白不同.
- (II) PcoC具有四角形结构,含有歇斯蒂丁连接体,而 (I) PcoC具有由两个氨酸残留物协调的三角形位点.
结论:
- PcoC代表了第一个具有丰富 metionin 蛋白质铜结合部位的良好特征的例子.
- 这一发现揭示了一种新型的生物铜协调化学.
- 在PcoC中独特的氨酸结合对于其在抗铜性作用至关重要.
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