Kataev Evgeny A, Shumilova Tatiana A
Institute of Chemistry, Faculty of Natural Sciences, Technische Universität Chemnitz, 09107 Chemnitz, Germany.
Molecules. 2015 Feb 16;20(2):3354-70. doi: 10.3390/molecules20023354.
Phosphates are ubiquitous in biology and nearly half of all proteins interact with their partners by means of recognition of phosphate residues. Therefore, a better understanding of the phosphate ion binding by peptidic structures is highly desirable. Two new receptors have been designed and synthesized and their anion binding properties in an acetonitrile solution have been determined. The structure of hosts mimics a part of the kinase active site that is responsible for the recognition of the phosphate residue. New hosts contain additional free amino groups with the aim to facilitate coordination of protonated anions, such as dihydrogen phosphate. According to spectrophotometric measurements, stepwise 1:1 and 1:2 binding modes have been observed for both receptors in the presence of acetate, hydrogen sulfate and dihydrogen phosphate. Compared with the acyclic receptor, the macrocyclic receptor has demonstrated a remarkably enhanced selectivity for dihydrogen phosphate over other anions. Fluorometric measurements have revealed different responses of the acyclic and macrocyclic receptors towards anions. However, in both cases, a 5-8 nm hypsochromic shift of fluorescence maximum has been observed upon interaction of acetate and dihydrogen phosphate with receptors.
磷酸盐在生物学中无处不在，几乎一半的蛋白质通过识别磷酸残基与它们的伙伴相互作用。因此，非常需要更好地理解肽结构对磷酸根离子的结合。已经设计并合成了两种新的受体，并测定了它们在乙腈溶液中的阴离子结合特性。主体结构模仿了激酶活性位点中负责识别磷酸残基的部分。新的主体含有额外的游离氨基，目的是促进质子化阴离子（如磷酸二氢根）的配位。根据分光光度测量，在存在乙酸根、硫酸氢根和磷酸二氢根的情况下，两种受体均观察到逐步的1:1和1:2结合模式。与非环状受体相比，大环受体对磷酸二氢根相对于其他阴离子表现出显著增强的选择性。荧光测量揭示了非环状和大环受体对阴离子的不同响应。然而，在两种情况下，乙酸根和磷酸二氢根与受体相互作用时，均观察到荧光最大值有5 - 8 nm的紫移。
