1型铜位的循环收缩突变发生
Sachiko Yanagisawa1, Christopher Dennison
1School of Natural Sciences, Bedson Building, University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU, UK.
Journal of the American Chemical Society
|December 2, 2004
概括
缩短 cupredoxins 中的铜结合环,可以微调 histidine 连接体.
科学领域:
- 生物化学 生物化学
- 生物有机化学 生物有机化学
- 蛋白质工程是指蛋白质工程.
背景情况:
- 1型铜蛋白,如铜素,是重要的电子转移剂.
- 活性部位结构,特别是铜结合环,影响蛋白质功能.
- 了解结构功能关系是设计新型金属蛋白的关键.
研究的目的:
- 为了研究循环收缩对1型铜中心在铜毒素支架中的影响.
- 探索如何缩短amicyanin循环影响铜位属性和氧化还原活性.
- 阐明循环长度在调整蛋白质电化学和电子转移中的作用.
主要方法:
- 将已知最短的1型铜结合环 (amicyanin) 引入不同的cupredoxinβ桶支架中.
- 使用光谱和电化学技术来描述由此产生的循环收缩变体.
- 分析结构变化及其与改变的功能性质的相关性.
主要成果:
- 循环收缩产生了功能性1型铜位点,在所有变体中具有真实的特性.
- 希斯提丁pK (a) 值增加,接近友素的值,表明循环长度调整了这个参数.
- 减少潜力略有下降,电子自我交换率显示出不同的反应,取决于脚手架.
- 循环收缩有利于Cu ((II) 活跃的地点环境.
结论:
- 铜结合环的长度是1型铜中心属性的关键决定因素,包括histidine pK(a) 和性特征.
- 循环收缩微调氧化还原潜力并影响电子转移速率,具有脚手架特定的效应.
- 通过循环修饰的蛋白质工程提供了一个调节金属蛋白功能的途径.
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