Metal Fluorides: Tools for Structural and Computational Analysis of Phosphoryl Transfer Enzymes.
Metal Fluorides: Tools for Structural and Computational Analysis of Phosphoryl Transfer Enzymes.
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DOI：
10.1007/s41061-017-0130-y
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发表时间：
2017-04
期刊：
影响因子：
--
通讯作者：
Blackburn GM
中科院分区：
文献类型：
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作者：
Jin Y;Molt RW Jr;Blackburn GM
磷酰基PO3-是磷生物化学中的动态结构单元。它从供体原子转移到受体原子，氧比氮、碳或硫更普遍，是涉及磷酸酯、酸酐、酰胺酸盐和硫代磷酸盐的大多数酶催化反应的核心。偶然发现磷酰基可以通过用MgF3-或AlF4-取代PO3-来标记，这一偶然发现支持了金属氟化物(MFX)络合物在酶促磷酰转移反应中模拟过渡态的应用，具有足够的稳定性，可用于实验分析。固体中的蛋白质结晶学和溶液中的19F核磁共振使人们能够准确地直接观察到包含MFX过渡态模型的三元和四元蛋白质络合物。这些研究支持了一种全新的酶催化机制，用于广泛的磷酰化转移过程，如激酶、磷酸酶、磷酸变位酶和磷酸水解酶。这些结果无一例外地支持了三方双锥几何构型(TBP)用于磷酰基转移的协同的、在线的立体化学。QM计算证实了TBP MFX络合物作为真实过渡态的可靠模型的有效性，提供了相似的键长、与必需金属离子的配位以及几乎相同的氢键网络。酶过渡态中形成键的物种之间的反应物轨道重叠的蛋白质控制的出现是一个新的具有挑战性的主题，具有更广泛的探索。
The phosphoryl group, PO3 –, is the dynamic structural unit in the biological chemistry of phosphorus. Its transfer from a donor to an acceptor atom, with oxygen much more prevalent than nitrogen, carbon, or sulfur, is at the core of a great majority of enzyme-catalyzed reactions involving phosphate esters, anhydrides, amidates, and phosphorothioates. The serendipitous discovery that the phosphoryl group could be labeled by “nuclear mutation,” by substitution of PO3 – by MgF3 – or AlF4 –, has underpinned the application of metal fluoride (MFx) complexes to mimic transition states for enzymatic phosphoryl transfer reactions, with sufficient stability for experimental analysis. Protein crystallography in the solid state and 19F NMR in solution have enabled direct observation of ternary and quaternary protein complexes embracing MFx transition state models with precision. These studies have underpinned a radically new mechanistic approach to enzyme catalysis for a huge range of phosphoryl transfer processes, as varied as kinases, phosphatases, phosphomutases, and phosphohydrolases. The results, without exception, have endorsed trigonal bipyramidal geometry (tbp) for concerted, “in-line” stereochemistry of phosphoryl transfer. QM computations have established the validity of tbp MFx complexes as reliable models for true transition states, delivering similar bond lengths, coordination to essential metal ions, and virtually identical hydrogen bond networks. The emergence of protein control of reactant orbital overlap between bond-forming species within enzyme transition states is a new challenging theme for wider exploration.