PDF(Pubmed)
Abstract：
Pyridoxal-S-methyl-isothiosemicarbazone (PLITSC) is a member of an important group of ligands characterized by different complexation modes to various transition metals. In this contribution, a new complex containing two differently protonated PLITSC ligands ([Fe(PLITSC-H)(PLITSC)]SO4)∙2.5H2O was obtained. The crystal structure was solved by the X-ray analysis and used further for the optimization at B3LYP/6-311++G(d,p)(H,C,N,O,S)/def2-TZVP(Fe) level of theory. Changes in the interaction strength and bond distance due to protonation were observed upon examination by the Quantum Theory of Atoms in Molecules. The protein binding affinity of [Fe(PLITSC-H)(PLITSC)]SO4 towards transport proteins (Bovine Serum Albumin (BSA) and Human Serum Albumin (HSA)) was investigated by the spectrofluorimetric titration and molecular docking. The interactions with the active pocket containing fluorescent amino acids were examined in detail, which explained the fluorescence quenching. The interactions between complex and DNA were followed by the ethidium-bromide displacement titration and molecular docking. The binding along the minor groove was the dominant process involving complex in the proximity of DNA.
摘要：
吡哆醛-S-甲基-异硫氨基脲（PLITSC）是一类重要配体的成员，其特征在于与各种过渡金属的络合模式不同。在这一贡献中,获得了包含两个不同质子化的PLITSC配体（[Fe（PLITSC-H）（PLITSC）]SO4）的新络合物2.5H2O。通过X射线分析解决了晶体结构，并进一步用于B3LYP/6-311G的优化（d，P)(H,C,N,O,S)/def2-TZVP(Fe)理论水平。通过分子中原子的量子理论检查，观察到由于质子化引起的相互作用强度和键合距离的变化。通过荧光光谱滴定和分子对接研究了[Fe（PLITSC-H）（PLITSC）]SO4对转运蛋白（牛血清白蛋白（BSA）和人血清白蛋白（HSA））的蛋白质结合亲和力。详细检查了与含有荧光氨基酸的活性口袋的相互作用，这解释了荧光猝灭。通过溴化乙锭置换滴定和分子对接来跟踪复合物与DNA之间的相互作用。沿着小沟的结合是涉及DNA附近复合物的主要过程。
