CBM33多糖氧化酶的铜活性位点是CBM33多糖氧化酶
Glyn R Hemsworth1, Edward J Taylor, Robbert Q Kim
1Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom.
Journal of the American Chemical Society
|April 2, 2013
概括
细菌多糖酸氧酶 (CBM33) 使用铜来稳定酶和降解纤维素,类似于真菌GH61酶. 这项研究揭示了结合铜的CBM33的结构和光谱细节,有助于从生物质生产生物燃料.
科学领域:
- 生物化学 生物化学
- 酶学 是一种酶学.
- 生物技术是生物技术.
背景情况:
- 金属依赖的多糖氧酶,GH61 (真菌) 和CBM33 (细菌),对于纤维素降解至关重要.
- 这些酶有可能将反燃生物质转化为生物燃料.
- 菌GH61酶具有独特的活性位点,其中包括单核铜离子和甲基化N终端的histidine.
研究的目的:
- 在结构和光谱学上表征结合铜的细菌CBM33酶.
- 阐明CBM33.33中的铜结合点和协调.
- 为了比较CBM33中的铜协调与真菌GH61.1.
主要方法:
- 电子偏磁共振 (EPR) X频段 Cu (II) -CBM33.3 的光谱学.
- 紫外线/Vis光谱法观察带协调.
- 在溶液和晶体中对Cu-CBM33进行X射线吸收/光研究.
- 对于3D结构的确定,X射线晶体学.
主要成果:
- CBM33在单核部位表现出高亲和度的铜结合,增强了酶的稳定性.
- EPR光谱检测发现了一个单核型2铜部位,轴坐标扭曲.
- 观察到阿齐德协调,由390nm的紫外线/紫外线吸收带表示.
- X射线研究证实了铜的光还原到Cu (I),并揭示了由两个histidines和N端的T形结合.
结论:
- 细菌CBM33酶与真菌GH61酶类似地结合铜.
- 在CBM33中特征的铜部位在结构上类似于GH61.1.
- 这种结构相似性为这些金属酶的纤维素降解机制提供了洞察力.
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