Ionic liquid solvation of proteins in native and denatured states

Autor(es)

Piccoli, Vinicius ; Martinez, Leandro

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF MOLECULAR LIQUIDS; v. 363, p. 15-pg., 2022-07-30.

Resumo

Ionic liquids (ILs) are utilized as enzymatic reaction solvents and as protein structure protectants or denaturants in biotechnological applications. They can develop a wide spectrum of interactions with macromolecules due to their chemical complexity. Understanding how ILs interact with protein confor-mations is crucial to fine-tuning their action. Here, we investigate the solvation of different ubiquitin folding states in aqueous solutions of four ionic liquids formed by the combination of the cations 1-Ethyl-3-methylimidazolium (EMIM), and 1-Butyl-3-methylimidazolium (BMIM), and the anions Tetrafluoroborate (BF4), and Dicyanamide (DCA). The structure and thermodynamics of the interactions between the protein in various denaturation states and the ILs were evaluated using minimum-distance distribution functions (MDDFs) and the Kirkwood-Buff (KB) theory of solutions. Under most circum-stances, the ILs preferentially solvate the protein structures, and are thus considered denaturants. However, even when preferential hydration is obtained for the native structure, denaturation is favored because of strong IL preferential binding to the denatured states. As the protein undergoes denaturation, its surface area increases, and residues with decreased polarity are exposed. The ILs interact favorably with these residues, excluding water, cooperatively stabilizing the exposure of the protein core. Strong specific DCA-protein interactions, which jointly draw cations to the protein surface due to electrostatic correlations, render ILs containing the anion DCA stronger denaturants than those containing BF4.(c) 2022 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 20/04916-3 - Efeitos de íon comum e múltiplos eletrólitos na solvatação de proteínas por líquidos iônicos
• Beneficiário: Vinicius Piccoli
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 13/08293-7 - CECC - Centro de Engenharia e Ciências Computacionais
• Beneficiário: Munir Salomao Skaf
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 18/24293-0 - Métodos computacionais de otimização
• Beneficiário: Sandra Augusta Santos
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 18/14274-9 - Determinação de estruturas de proteínas usando restrições de distância obtidas de experimentos de ligação cruzada: métodos computacionais e aplicações
• Beneficiário: Leandro Martinez
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 10/16947-9 - Estrutura, dinâmica e função em proteínas: simulação computacional e desenvolvimento de algoritmos
• Beneficiário: Leandro Martinez
• Modalidade de apoio: Auxílio à Pesquisa - Regular