含有机配体的活性双过氧钒配合物与组氨酸的相互作用研究

在合成和表征了4种具有较强生物活性双过氧钒配合物K_3[VO(O_2)_2(ox)]· 2H_2O，Na[VO(O_2)_2(bipy)]·5H_2O，K[VO(O_2)_2(phen)]·3H_2O和K_2[VO (O_2)_2(pic)]·2H_2O[分别缩写为pV(ox)，pV(bipy)，pV(phen)和pV(pic)，其中 ox为草酸根，bipy为2,2'-联吡啶，phen为邻菲咯啉，pic为2-羧酸吡啶负离子]的 基础上，利用多种NMR技术和电喷雾质谱（ESI-MS）研究了这4种含有机配体双过氧 钒酸合物与组氨酸（His）在溶液中的相互作用以及反应物浓度、时间、pH等对相 互作用体系的影响。~(51)V NMR跟踪监测的结果表明：双过氧钒配合物pV(ox)和 pV(pic)与His在中性水溶液中存在强配位相互作用，而pV(bipy)和pV(phen)与His 在中性水溶液中无明显作用。我们还利用谱学方法确定了pV(ox)和His相互作用后 所生成产物是pV(ox)分别与His在中性水溶液中无明显作用。我们还利用谱学方法 确定了pV(ox)和His相互作用后所生成产物是pV(ox)分别与His咪唑基上的3-N和1- N配位的一对异构体。

Studies on the Interactions between Bioactive Peroxovanadium Complexes bearing Organic Ligands and Histidine

In order to explore the structure-activity relationship and molecular mechanism of the specific recognition between peroxovanadium (pV) complexes bearing organic ligands and the target enzymes of tyrosine phosphatase, several NMR techniques and ESI-MS were used to study the interactions of four pV complexes {pV(ox), pV(bipy), pV(phen) and pV(pic), where pV = [VO(O_2)_2L]~(n~-), in which L = oxalic acid histidine. Strong coordination interactions between imidazole of histidine and vanadium of pV(ox) or pV(pic) were observed in neutral solution, while there are not obvious interactions between histidine and pV(bipy) or pV(phen). All ~(13)C and ~1H NMR signals of 1:1 stoichiometric mixture of pV(ox) and histidine were assigned. Spectroscopic studies demonstrated that new complexes in the mixture of pV(ox) and histidine area pair of isomers in which the vanadium in pV(ox) binding to the 3-N and 1-N of the imidazole ring. Moreover, the results of effective factors on the interaction system indicated that the new isomers were stable under the condition of physiological pH and the structure-activity relationship of these pV complexes may be relevant to their specific recognition towards histidine residues in tyrosine phosphatase.