Molecular Mechanism for the Interactions of Hofmeister Cations with Macromolecules in Aqueous Solution
| العنوان: | Molecular Mechanism for the Interactions of Hofmeister Cations with Macromolecules in Aqueous Solution |
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| المؤلفون: | Chad I. Drexler, Halil I. Okur, Paul S. Cremer, Ellen E Bruce, Bradley A. Rogers, Nico F. A. van der Vegt, Sina Stegmaier, Sylvie Roke |
| المساهمون: | Okur, Halil I. |
| المصدر: | Journal of the American Chemical Society |
| بيانات النشر: | American Chemical Society (ACS), 2020. |
| سنة النشر: | 2020 |
| مصطلحات موضوعية: | chemistry.chemical_classification, Aqueous solution, Inorganic chemistry, Salt (chemistry), General Chemistry, 010402 general chemistry, 01 natural sciences, Biochemistry, Chloride, Catalysis, 0104 chemical sciences, chemistry.chemical_compound, Colloid and Surface Chemistry, chemistry, Amide, Side chain, medicine, Counterion, Solubility, Macromolecule, medicine.drug |
| الوصف: | Ion identity and concentration influence the solubility of macromolecules. To date, substantial effort has been focused on obtaining a molecular level understanding of specific effects for anions. By contrast, the role of cations has received significantly less attention and the underlying mechanisms by which cations interact with macromolecules remain more elusive. To address this issue, the solubility of poly(N-isopropylacrylamide), a thermoresponsive polymer with an amide moiety on its side chain, was studied in aqueous solutions with a series of nine different cation chloride salts as a function of salt concentration. Phase transition temperature measurements were correlated to molecular dynamics simulations. The results showed that although all cations were on average depleted from the macromolecule/water interface, more strongly hydrated cations were able to locally accumulate around the amide oxygen. These weakly favorable interactions helped to partially offset the salting-out effect. Moreover, the cations approached the interface together with chloride counterions in solvent-shared ion pairs. Because ion pairing was concentration-dependent, the mitigation of the dominant salting-out effect became greater as the salt concentration was increased. Weakly hydrated cations showed less propensity for ion pairing and weaker affinity for the amide oxygen. As such, there was substantially less mitigation of the net salting-out effect for these ions, even at high salt concentrations. |
| وصف الملف: | application/pdf |
| تدمد: | 1520-5126 0002-7863 |
| DOI: | 10.1021/jacs.0c07214 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::600516a85f8e2a19a6c04248d55bdca3 https://doi.org/10.1021/jacs.0c07214 |
| Rights: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....600516a85f8e2a19a6c04248d55bdca3 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15205126 00027863 |
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| DOI: | 10.1021/jacs.0c07214 |