碳酸酐酶模型化合物的合成、表征及其催化性能研究

Investigation on Synthesis,Characterization and Catalytic Activity of Model Complexes of Carbonic Anhydrase

模拟碳酸酐酶的活性中心结构,以三(取代吡唑基)硼氢根[Tp^(R,R^1)]^-为配体,合成了一系列金属配合物Tp^(R,R^1)MX[R=Ph,2＇—thie(2＇—噻吩基),Me;R^1=Ph,2＇—thie,Me;M=Co,Ni,Cu,Zn,Cd;X=Cl,NO_3,CH_3COO]共13个,均经元素分析,IR,~1HNMR谱表征.选取其中5个有代表性的配合物,采用Stopped-flow技术,研究了模型物催化CO_2可逆水合反应的动力学,结果表明具备酶促反应动力学的一般特征.详细考察了溶液pH值、模型物的结构(尤其是中心金属离子的电子结构)、浓度对该反应的影响,得出一些重要的结果.计算出该反应有、无催化剂时的活化能,从本质上阐明了反应活化能降低是模型物加速反应的根本原因.

To model active site structure of carbonic anhydrase (CA), we synthesized a series of metal complexes supported by tris(substituted pyrazolyl) hydroborato ligands TpR,R1MX (R = Ph, 2' - thie, Me; R1 = Ph, 2' - thie, Me; M = Co, Ni, Cu, Zn, Cd; X = Cl, NO3, CH3COO). These complexes were all characterized by elemental analysis, IR, and 1H NMR spectroscopy. Activity of five representatives selected from these complexes in catalyzing reversible hydration reaction of CO2 were investigated by the stopped - flow technique. It was showed that the reaction had general dynamic characteristics of enzyme - catalyzed reaction. The activity varied with the pH of reaction system, the structure (especially electric structure of metal ion) and concentration of the model complexes, along with some other important results were obtained. The activation energy of dehydration reaction in the presence and absence of model complexes were calculated, which may interpret well that the higher reaction rate essentially resulted from the decrease in activation energy of the reaction.