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 (MF _x ) 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 MF _x 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 MF _x 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.

磷酰基 PO ₃ ^–是磷的生物化学中的动态结构单元。它从供体转移到受体原子，其中氧比氮、碳或硫更普遍，是大多数酶催化反应的核心，涉及磷酸酯、酸酐、酰胺化物和硫代磷酸酯。磷酰基可以通过“核突变”标记的偶然发现，即通过用 MgF ₃ ^-或 AlF ₄ ^{-取代 PO} ₃ ^，支持了金属氟化物 (MF _x ) 配合物模拟酶促磷酰基转移反应的过渡态，具有足够的稳定性用于实验分析。固态蛋白质晶体学和溶液中的¹⁹ F NMR 可以直接观察包含 MF _x过渡态模型的三元和四元蛋白质复合物。这些研究支持了一种全新的酶催化机制方法，用于各种磷酸转移过程，如激酶、磷酸酶、磷酸变位酶和磷酸水解酶。结果无一例外地认可了三角双锥几何 (tbp) 用于磷酸转移的协同、“在线”立体化学。QM 计算确定了 tbp MF _{x的有效性} 配合物作为真正过渡态的可靠模型，提供相似的键长、与基本金属离子的配位以及几乎相同的氢键网络。酶过渡态内成键物种之间反应物轨道重叠的蛋白质控制的出现是更广泛探索的一个新的具有挑战性的主题。