用模型聚氨酯研究离子-大分子相互作用。

Ion-macromolecule interactions studied with model polyurethanes.

机构信息

INAMAT (Institute for Advanced Materials) y Departamento de Física, Universidad Pública de Navarra (UPNA), Centro Jerónimo de Ayanz, Campus Arrosadía, 31006 Pamplona, Spain; POLYMAT and Polymer Science and Technology Department, Faculty of Chemistry, University of the Basque Country UPV/EHU, Paseo Manuel de Lardizábal 3, 20018 Donostia-San Sebastián, Spain.

Grupo de Investigación Química Inorgánica, Departamento de Química Aplicada, Universidad del País Vasco UPV/EHU, Avda. Manuel de Lardizábal 3, 20018 San Sebastian, Spain; IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.

出版信息

J Colloid Interface Sci. 2018 Jan 1;509:102-112. doi: 10.1016/j.jcis.2017.08.099. Epub 2017 Sep 2.

DOI:10.1016/j.jcis.2017.08.099

PMID:28892743

Abstract

HYPOTHESIS

The solubility and self-assembly of macromolecules in solution can be tuned by the presence of different salts. Natural proteins have been long manipulated with the aid of salts, and natural silk is processed in the gland tip across a gradient of different salts which modifies its solubility. Hence, the comprehensive understanding of the role of ion-macromolecule interactions should pave the way towards a biomimetic processing of macromolecules.

EXPERIMENTS

A model polyurethane catiomer (PU) with high density of hydrogen donors and acceptors (similar to proteins) has been designed and synthesized in order to study ion-macromolecule interactions by means of dynamic light scattering (DLS), infrared spectroscopy (FTIR) and nuclear magnetic resonance (C NMR).

FINDINGS

The PU solubility in the presence of different salts exhibited a reversed anion Hofmeister series (i.e., the anion ability to precipitate the PU was F<Cl<Br<NO<CHCOO<HPO<HCO<I<ClO<SCN). The ordering of this series was found to be predicted, for the first time, by the Born-Landé-Ephraim-Fajans-Bjerrum model used here to estimate the degree of macromolecule-ion pairing in water solution. This work also helps understanding the role of cations and anions nature on their interaction with macromolecules backbone.

摘要

假设

在溶液中，通过添加不同的盐可以调节大分子的溶解度和自组装。长期以来，人们一直在利用盐来操纵天然蛋白质，而天然丝则在腺体尖端经过不同盐的梯度处理，从而改变其溶解度。因此，全面了解离子-大分子相互作用的作用应该为大分子的仿生加工铺平道路。

实验

为了通过动态光散射（DLS）、红外光谱（FTIR）和核磁共振（C NMR）研究离子-大分子相互作用，设计并合成了一种具有高密度供体和受体的模型聚氨酯阳离子（PU）（类似于蛋白质）。

结果

不同盐存在下的 PU 溶解度表现出反转的阴离子 Hofmeister 序列（即阴离子沉淀 PU 的能力为 F<Cl<Br<NO<CHCOO<HPO<HCO<I<ClO<SCN）。首次发现，该序列的排序可以通过这里用于估计水溶液中大分子-离子配对程度的 Born-Landé-Ephraim-Fajans-Bjerrum 模型来预测。这项工作还有助于理解阳离子和阴离子性质在与大分子主链相互作用中的作用。