Journal of Inorganic Biochemistry ( IF 3.9 ) Pub Date : 2018-04-06 R. Bregier-Jarzębowska, L. Łomozik, A. Gąsowska
Potentiometric and NMR spectroscopic studies of the nucleotide (NucP)/polyamine (PA) system (where NucP = CDP, CTP, PA = putrescine or spermidine) revealed the formation of molecular complexes (NucP)(Hx+y)(PA) (where Hx+y = number of protons; x - from NucP and y - from PA). Their thermodynamic parameters were determined and the modes of their interactions were proposed. The main reaction centers were found to be the protonated amine groups of polyamine (positive centers) and phosphate groups of nucleotide (negative centers). The pH ranges in which the complex occurs correspond to those of amine protonation and -PO3x- group deprotonation, which unambiguously confirms the dipole-dipole type of interaction. In the pH range of total deprotonation of
NHx+ groups from the polyamine, the molecular complexes disappear. The equilibrium and spectroscopic studies of the ternary systems Cu(II)/NucP/PA evidenced the formation of Cu(NucP)Hx+y(PA) type coordination compounds and Cu(NucP)⋯(PA)(Hx) type molecular complexes with polyamine in the outer coordination sphere. The main sites of metal ion bonding in the latter species are the phosphate groups of the nucleotide, while in the coordination compounds – besides the phosphate groups – also the donor nitrogen atoms from the polyamines. In this paper we have also quantitatively calculated the effect of metal ions on the formation of the molecular complexes.中文翻译：
铜离子对胞苷5'-二磷酸或胞苷5'-三磷酸与生物胺腐胺或亚精胺之间非共价相互作用的影响
核苷酸（NucP）/多胺（PA）系统（其中NucP = CDP，CTP，PA =腐胺或亚精胺）的电位和NMR光谱研究 揭示了分子复合物（NucP）（H x + y）（PA）的形成（其中H x + y =质子数； x-来自NucP，y-来自PA）。确定了它们的热力学参数，并提出了它们的相互作用方式。发现主要反应中心是多胺的质子化胺基团（正中心）和核苷酸的磷酸基团（负中心）。发生络合物的pH范围对应于胺质子化和-PO 3 x-基团去质子化，这无疑证实了偶极-偶极子相互作用的类型。在pH范围内的全部去质子化
来自多胺的NH x +基团，分子配合物消失。三元体系Cu（II）/ NucP / PA的平衡和光谱研究证明了Cu（NucP）H x + y（PA）型配位化合物和Cu（NucP）⋯（PA）（H x）型分子的形成在外部配位领域与多胺形成配合物。后一种物质中金属离子键的主要位点是核苷酸的磷酸基，而在配位化合物中，除磷酸基外，还有来自多胺的供体氮原子。在本文中，我们还定量计算了金属离子对分子配合物形成的影响。
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