STRUCTURE OF TWO NIFE CLUSTERS IN CODH FROM CLOSTRIDIUM THERMOACETICUM

我们建议研究一氧化碳的两个镍中心 独立产热乳酸梭菌脱氢酶 使用镍和钴K边EXAFS。这项研究是由 最近发现用1，10-二氮杂菲处理该酶 仅从两个生命中心中的一个中心移除镍。以前的EXAFS 对这种酶的研究并没有导致一个独特的结构决定 因为这两个镍原子不是 光谱可分辨的。我们应该能够确定 用邻菲咯啉的Ni K边EXAFS研究一个中心的结构 处理过的酶，以及用Co K-EDGE研究另一个位置的结构 钴取代邻菲咯啉处理酶的EXAFS分析。

We propose to examine the two Ni centers of carbon monoxide dehydrogenase enzyme from Clostridium thermoacticum independently using Ni and Co K-edge EXAFS. This study is made possible by the recent discovery that treatment of the enzyme with 1,10-phenanthroline removes the Ni from only one of the two NiFe centers. Previous EXAFS work on this enzyme has not led to a unique structural determination of the NiFe clusters because the two Ni sites are not spectroscopically distinguishable. We should be able to determine the structure of one site using Ni K-edge EXAFS of the phenanthroline treated enzyme, and the structure of the other site using Co K-edge EXAFS of the Co substituted phenanthroline treated enzyme.