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用钒-51核磁共振方法研究钒酸根在不同浓度和离子强度下,在生理pH水溶液中的物种分配.研究结果表明毫摩尔级浓度的钒酸根主要以中心钒原子为四面体构型的单体、二聚、四聚和五聚体存在.通过比较所得的平衡常数说明在离子强度降低时,钒酸根的聚合度下降对于钒酸根-ADP体系,从所显示的核磁谱变化通过计算得到相应的结合平衡常数,说明主要发生的反应一是形成ATP类似物ADPV(V代表四面体构型的单体钒酸根);二是在ADP浓度相对高时,钒酸根与ADP核糖基上2’,3’-顺位羟基同时作用形成2:2配比的、钒原子为五配位三角双锥构型的配合物.在钒酸根-ADP体系中加入Mn~(2+)后,~(51)V NMR的变化说明ATP的类似物ADPV中β-磷酸根和γ-钒酸根可以协同螯合Mn~(2+),表明形成了Mg~(2+)-ATP的类似物Mn~(2+)-ADPV.
Vanadium-51 nuclear magnetic resonance method was used to study the species distribution of vanadate in physiological pH aqueous solution under different concentrations and ionic strengths.The results show that the concentration of vanadate in the millimolar concentration is mainly dominated by tetrahedral vanadium atom , Dimers, tetramers and pentamers.The comparison of the resulting equilibrium constants shows that the degree of polymerization of vanadate decreases as ionic strength decreases. For the vanadate -ADP system, the change from the indicated NMR spectrum is calculated In combination with the equilibrium constants, the main reaction is the formation of an ATP analog ADPV (V represents tetrahedral configuration of the monomer vanadate); the second is relatively high concentration of ADP, vanadate and ADP ribose 2 ’, 3 ’- the cis hydroxyl groups formed a complex with a 2: 2 ratio of vanadium atoms to the five-coordinate trigonal bipyramidal structure at the same time.When Mn 2+ was added into vanadate -ADP system, The changes of V NMR indicate that β-phosphate and γ-vanadate in ADPV, an ATP analogue, can chelate Mn 2+ synthetically, indicating that Mg 2+ (2+) ) -ADPV.