STRUCT OF YEAST GUANYLATE KINASE COMPLEXED W/BISUBSTRATE MIMICKING INHIBITOR

金属取代的血红蛋白是一种很好的研究手段 血红素铁在氧结合和释放中的作用。当 肌红蛋白中铁中心被钴取代，钴被钴取代 肌红蛋白已被证明可以可逆地结合氧气。然而， 钴肌红蛋白(梳状)的氧亲和力低于亚铁 肌红蛋白(Mb)。对梳子的EPR研究表明，与原生Mb不同 其中脱氧Mb是高自旋(S=2)，而氧Mb是低自旋(S=0)， 梳子的氧态和脱氧态都是低自旋的(S==)。这意味着 两者脱氧态的结构/电子差异 物种，这可能是导致梳子的氧亲和力较低的原因。 在光束线U4B上，我们得到了钴的L边光谱 肌红蛋白处于氧化和脱氧状态。实验数据 证明了脱氧梳和氧梳的L边谱是 显著不同，对应于钴氧化的不同 这两个物种之间的状态和位置对称性。在未来， 我们将研究Oxy comb照片产品，它是由 Oxy Comb在15K的光解，并已被证明是 电子不同于EPR脱氧梳子。最后，我们会 继续研究钴的亚铁血红素模型化合物以协助 在我们对蛋白质种类的多重模拟中。

Metal-substituted hemeproteins are an excellent means of studying the role of the heme iron in oxygen-binding and release. When the iron center in myoglobin is replaced by cobalt, cobalt-substituted myoglobin has been shown to reversibly bind oxygen. However, the oxygen affinity for cobaltous myoglobin (CoMb) is lower than ferrous myoglobin (Mb). EPR studies on CoMb have shown that, unlike native Mb where deoxy Mb is high spin (S=2) and oxy Mb is low spin (S=0), the oxy- and deoxy- states of CoMb are both low spin (S==). This implies structural/electronic differences in the deoxy- states of the two species, which may contribute to the lower oxygen affinity for CoMb. At Beamline U4B, we have obtained the L-edge spectra of cobaltous myoglobin in the oxy- and deoxy- states. The experimental data demonstrate that the L-edge spectra of Deoxy CoMb and Oxy CoMb are noticeably different, corresponding to differences cobalt oxidation states and site symmetries between these two species. In the future, we will examine the Oxy CoMb photoproduct, which is generated by photolysis of Oxy CoMb at 15 K, and has been shown to be electronically different than deoxy CoMb by EPR. Finally, we will continue to examine cobaltous heme model compounds in order to assist in our multiplet simulations of the protein species.