鲁比斯科的二氧化碳和氧气分布表明,这个小子单元可以作为二氧化碳储存库
Michiel van Lun1, Jochen S Hub, David van der Spoel
1Department of Molecular Biology, Swedish University of Agricultural Sciences , Box 590, S-751 24 Uppsala, Sweden.
Journal of the American Chemical Society
|February 6, 2014
概括
利布洛斯-1,5-双酸碳氧化酶/氧化酶 (Rubisco) 结合二氧化碳 (CO2) 比氧 (O2) 更强,其中的小子单元作为二氧化碳储存器. 这种相互作用将二氧化碳引导到活性部位,影响光合作用效率.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 光合作用研究研究 光合作用研究
背景情况:
- 蛋白质-气体相互作用在生物过程中至关重要.
- 利布洛斯-1,5-双酸碳氧化酶/氧化酶 (Rubisco) 酶催化竞争的碳氧化和氧化反应,涉及CO2和O2.
- 鲁比斯科的氧化减少了光合作用的生产力.
研究的目的:
- 为了研究CO2和O2在鲁比斯科和周围的迁移.
- 了解CO2和O2与鲁比斯科的结合亲和力.
- 为了阐明气体进入鲁比斯科活跃地点的机制.
主要方法:
- 用分子动力学模拟来研究气体迁移和结合.
- 分析的重点是Rubisco氨基酸残留物和气体分子之间的相互作用.
- CO2和O2的结合强度和通路的比较.
主要成果:
- 在相同度下,与O2相比,Rubisco对CO2具有更强的结合亲和力.
- 具有小型疏水性侧链的氨基酸是吸引二氧化碳的关键,突出了疏水效应.
- 鲁比斯科的小子单元与大子单元相比,约有两倍的二氧化碳.
- 没有发现气体进入的明显空洞;二氧化碳通过围绕活动部位开口的绑定区域引导.
结论:
- 鲁比斯科的小子单位可以作为二氧化碳储存储库.
- 疏水性相互作用在二氧化碳与鲁比斯科结合中起着重要作用.
- 将二氧化碳输送到活性部位的机制涉及特定的结合区域,而不是通过空洞进行简单的扩散.
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