Structures and Reactivities of Quaternary Metal Complexes as Enzyme Models

作为酶模型的四元金属配合物的结构和反应性

基本信息

批准号：
02453039
负责人：
YAMAUCHI Osamu
金额：
$ 3.26万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-02453039/
关键词：
Enzyme model metal complex Quaternary metal complex Ligand-ligand interaction Aromatic ring stacking Pterin-Cu (II) complex Tetrahydropterin Pt (II) complex containing an aromatic ring DNA-intercalator adduct model 四元錯体形成反応安定度定数プテリン含

项目摘要

With a view to elucidating the structures and reaction mechanisms of metalloenzyme-cofactor-substrate intermediate complexes, we investigated the structures, stabilities, and reactivities of ternary and quaternary complex systems as biological models.1. Aromatic ring stacking in ternary Cu (II) complexes, [Cu (bpy) (L-Trp) ClO_4]and[Cu (bpy) (L-Tyr)ClO_4]・2H_2O (bpy = 2, 2'-bipyridine ; Trp =tryptophan ; Tyr = tyrosine), has been established in the solid state between bpy and the side chain aromatic ring of Trp and Tyr, respectively, by X-ray crystal structure analysis. Upon phosphorylation of the Tyr phenol OH group, the phenol ring is involved in electrostatic interactions with the charged side group of arginine or lysine coordinated to the same Cu (II) ion. The result suggests the possibility that Tyr phosphorylation in proteins causes the change in the mode of interactions between the side chain groups of amino acid residues and thus gives rise to protein conformational changes.2. … More Adduct formation between platinum DNA intercalators[Pt (L) (en)] (L = bpy, 1, 10-phenanthroline (plien), 3, 4, 7, 8tetramethyl-1, 10-phenanthroline (Me_4phen) ) and mononucleotides (NMP = AMP, GMP, CMP) has been studied by spectroscopic methods. [pt (Me_4phen) (en)]with the largest hydrophobic area has been found to form the most stable adducts with NMP mainly through the stacking between L and the base moiety of NMP. It was concluded that the electrostatic interactions between the NMP phosphate group and Pt^<2+> or the coordinated en NH_2 group contribute to the adduct stability.3. Structures and stabilities of ternary and quaternary Cu (II) complexes involving a pterin cofactor model have been investigated by spectroscopic methods and potentiometry. Cu (bpy) (PC) (PC pterin-6-carboxylate) as a phenylalanine hydroxylase active site model was found to form quaternary complexes with L = imidazole (im), NH_3, or N_3^-, and the stability constants for the Cu (bpy) (PC) (im) system were successfully detemined by pH titrations at 25ﾟC and I = 0.1 M (KNO_3). The redox reactions between Cu (bpy)^<2+> and a tetrahydropterin were followed by spectroscopic and chromatographic methods, which revealed that the pterin is oxided to the dihydro form with, consumption of dioxygen. Less

为了阐明金属酶-Cofactor-substrate中间配合物的结构和反应机制，我们研究了三元和Quaternary复合体系统的结构，系统和反应性作为生物学模型。1。 Aromatic ring stacking in ternary Cu (II) complexes, [Cu (bpy) (L-Trp) ClO_4] and[Cu (bpy) (L-Tyr)ClO_4]・2H_2O (bpy = 2, 2'-bipyridine ; Trp =tryptophan ; Tyr = tyrosine), has been established in the solid state between bpy and the side chain aromatic ring of Trp and Tyr, respectively,通过X射线晶体结构分析。在Tyr苯酚OH组的磷酸化后，苯酚环与与同一Cu（II）离子配位的精氨酸或赖氨酸的带电侧组相互作用。结果表明，蛋白质中的Tyr磷酸化会导致氨基酸残基侧链组之间相互作用方式的变化，从而导致蛋白质构象变化。2。 …铂DNA介导剂[pt（l）（en）]之间的更多添加形成（L = BPY，1，10-磷酸（Plien），3、4、7、8tetramethyl-1、10-磷酸（ME_4PHEN））和单核苷酸（NMP = amp = amp，gmp，cmp，cmp，cmp，cmp，nmp = amp = amp）。 [pt（me_4phen）（en）]具有最大的疏水区域，它们主要通过L和NMP的基础部分之间的NMP形成最稳定的加合物。结论是，NMP磷酸组与PT^<2+>之间的静电相互作用或协调的EN NH_2组有助于加合稳定性3。涉及翼龙辅助因子模型的三元和第四纪铜（II）复合物的结构和稳定性已经通过光谱方法和势比率进行了研究。发现Cu（BPY）（PC）（PC pterin-6-羧酸盐）作为苯丙氨酸羟化酶活性位点模型，形成了与L =咪唑（IM），NH_3或N_3^ - 或N_3^ - 或N_3^ - 的第四级复合物，以及pH（IM）（IM）（IM）（IM）的稳定性常数。（kno_3）。 Cu（BPY）^<2+>与四氢翅目之间的氧化还原反应之后进行了光谱和色谱方法，这表明翼龙被氧化为二氧形式，并随着二氧化二氧化碳的消耗而氧化。较少的