ELECTRON TRANSFER PATHWAYS/BLUE COPPER PROTEINS

反硝化细菌是处理废物的重要媒介。 之一 硝酸盐最终转化为N2的电子转移途径 利用特别有效的产碱菌 faecalis菌株S-6，一种含铜亚硝酸盐还原酶，和一种蓝 蛋白质，其在正常情况下充当将蛋白质转移到细胞中的试剂， 电子的亚硝酸盐还原酶，也可以作为抑制剂， O2的存在。 我建议确定蓝铜蛋白的结构， 氧化和还原形式的分离度，使用标准品 X射线衍射技术。 长期目标是 理解分子水平上的电子转移， 关于电子转移蛋白质结构，促进转移， 提供了特异性，不同的蛋白质如何利用相同的 辅因子 部分序列信息和氨基酸组成 这种蓝色蛋白质的分子量介于另外两种蓝色铜 具有已知结构的蛋白质，质体蓝蛋白和天青蛋白，表明， 而A.粪蓝蛋白可能具有相同的发色团， 具有不同的折叠，并且很可能代表 这些I型蓝铜蛋白 因此，该结构确定将 提供了一个新的观点，生物体如何溶解，利用和调节， 电子转移辅因子 此外，由于其与 亚硝酸盐还原酶是一个很好的定义，它的结构也正在研究中。 我们最终可以直接研究电子 传输组件相互作用。

Denitrifying bacteria are important agents in managing waste. One of the electron transfer pathways in which nitrates are converted eventually to N2 utilizes, for the particularly potent denitrifying bacteria Alcaligenes faecalis Strain S-6, a copper containing nitrite reductase, and a blue protein which while normally acting as the agent which transfers an electron to the nitrite reductase, can also act as an inhibitor in the presence of O2. I propose to determine the structure of that blue copper protein to high resolution in both the oxidized and reduced forms, using standard techniques of X-ray diffraction. The long term objectives are to understand electron transfer at a molecular level, to understand what it is about electron transfer protein structures that facilitates transfer, what provides specificity, how different proteins make use of the same cofactor. Partial sequence information and the amino acid composition of this blue protein of molecular weight intermediate to two other blue copper proteins with known structure, plastocyanin and azurin, indicates that while A. faecalis blue protein probably has the same chromophore, it may have different folding, and may well represent a structural subclass of these Type I blue copper proteins. Thus this structure determination will afford a new view of how an organism solubilizes, utilizes and regulates an electron transfer cofactor. Moreover, since its interaction with the nitrite reductase is well defined, and its structure is also being worked on, we can eventually directly examine the question of how electron transfer components interact.