Pangavhane Sachin, Böhm Stanislav, Makrlík Emanuel, Ruzza Paolo, Kašička Václav
The Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic.
Faculty of Food and Biochemical Technology, University of Chemistry and Technology, Prague, Czech Republic.
Electrophoresis. 2017 Aug;38(16):2025-2033. doi: 10.1002/elps.201700141. Epub 2017 May 26.
ACE and density functional theory were employed to study the noncovalent interactions of cyclic decapeptide glycine-6-antamanide ([Gly ]AA), synthetic derivative of native antamanide (AA) peptide from the deadly poisonous fungus Amanita phalloides, with small cations (Li , Rb , Cs , NH , and Ca ) in methanol. The strength of these interactions was quantified by the apparent stability constants of the appropriate complexes determined by ACE. The stability constants were calculated using the nonlinear regression analysis of the dependence of the effective electrophoretic mobility of [Gly ]AA on the concentration of the above ions in the BGE (methanolic solution of 20 mM chloroacetic acid, 10 mM Tris, pH 7.8, containing 0-70 mM concentrations of the above ions added in the form of chlorides). Prior to stability constant calculation, the effective mobilities measured at actual temperature inside the capillary and at variable ionic strength of the BGEs were corrected to the values corresponding to the reference temperature of 25°C and to the constant ionic strength of 10 mM. From the above ions, Rb and Cs cations interacted weakly with [Gly ]AA but no interactions of [Gly ]AA with univalent Li and NH ions and divalent Ca ion were observed. The apparent stability constants of [Gly ]AA-Rb and [Gly ]AA-Cs complexes were found to be equal to 13 ± 4 and 22 ± 3 L/mol, respectively. The structural characteristics of these complexes, such as position of the Rb and Cs ions in the cavity of the [Gly ]AA molecule and the interatomic distances within these complexes, were obtained by the density functional theory calculations.
采用ACE和密度泛函理论研究了环十肽甘氨酸-6-鹅膏蕈氨酸（[Gly]AA）（来自剧毒真菌毒鹅膏菌的天然鹅膏蕈氨酸（AA）肽的合成衍生物）与甲醇中的小阳离子（Li⁺、Rb⁺、Cs⁺、NH₄⁺和Ca²⁺）之间的非共价相互作用。这些相互作用的强度通过ACE测定的相应配合物的表观稳定常数来量化。稳定常数是通过对[Gly]AA的有效电泳迁移率与BGE（20 mM氯乙酸、10 mM Tris、pH 7.8的甲醇溶液，含有以氯化物形式添加的0 - 70 mM上述离子）中上述离子浓度的依赖性进行非线性回归分析来计算的。在计算稳定常数之前，将在毛细管内实际温度和BGEs可变离子强度下测量的有效迁移率校正为对应于25°C参考温度和10 mM恒定离子强度的值。在上述离子中，Rb⁺和Cs⁺阳离子与[Gly]AA相互作用较弱，但未观察到[Gly]AA与单价Li⁺和NH₄⁺离子以及二价Ca²⁺离子之间的相互作用。发现[Gly]AA - Rb和[Gly]AA - Cs配合物的表观稳定常数分别等于13 ± 4和22 ± 3 L/mol。通过密度泛函理论计算获得了这些配合物的结构特征，如Rb⁺和Cs⁺离子在[Gly]AA分子腔内的位置以及这些配合物内的原子间距离。
