The pentacovalent phosphorus intermediate of a phosphoryl transfer reaction
The pentacovalent phosphorus intermediate of a phosphoryl transfer reaction
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DOI：
10.1126/science.1082710
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发表时间：
2003-03-28
期刊：
影响因子：
56.9
通讯作者：
Allen, KN
中科院分区：
文献类型：
--
作者：
Lahiri, SD;Zhang, GF;Allen, KN
酶提供了巨大的速率提升，是任何其他类型的催化剂无法比拟的。高能态在反应坐标上的稳定是酶催化能力的关键。我们报道了一种稳定在酶活性中心的高能反应中间体的原子分辨结构。磷酸化的β-磷酸葡萄糖变位酶在镁(II)辅因子和葡萄糖1-磷酸或葡萄糖6-磷酸的存在下结晶产生酶-镁(II)-葡萄糖1，6(双)磷酸络合物的晶体，其X射线衍射分别为1.2和1.4埃。该结构揭示了葡萄糖1，6-(双)磷酸的C(1)O向亲核的Asp8羧酸盐的磷酰化转移过程中形成的稳定的五价磷。
Enzymes provide enormous rate enhancements, unmatched by any other type of catalyst. The stabilization of high-energy states along the reaction coordinate is the crux of the catalytic power of enzymes. We report the atomic-resolution structure of a high-energy reaction intermediate stabilized in the active site of an enzyme. Crystallization of phosphorylated beta-phosphoglucomutase in the presence of the Mg(II) cofactor and either of the substrates glucose 1-phosphate or glucose 6-phosphate produced crystals of the enzyme-Mg(II)-glucose 1,6(bis)phosphate complex, which diffracted x-rays to 1.2 and 1.4 angstroms, respectively. The structure reveals a stabilized pentacovatent phosphorane formed in the phosphoryl transfer from the C(1)O of glucose 1,6-(bis)phosphate to the nucleophilic Asp8 carboxylate.