resumo
Distribution coefficients of various proteins were measured in aqueous Dextran-Ficoll, Dextran-PES, and Ficoll-PES two-phase systems, containing 0.15 M NaCl in 0.01 M phosphate buffer, pH 7.4. The acquired data were combined with data for the same proteins in different systems reported previously [29,30] and known solvatochromic solvent properties of the systems [17] to characterize the protein-solvent interactions. The relative susceptibilities of proteins to solvent dipolarity/polarizability, solvent hydrogen bond acidity, solvent hydrogen bond basicity, and solvent ability to participate in ion-ion and ion-dipole interactions were characterized. These parameters, which are representative of solute-solvent interactions, adequately described the partitioning of the proteins in each system. It was found that the relative susceptibilities of proteins to solvent dipolarity/polarizability are interrelated with their relative susceptibilities to solvent hydrogen bond acidity and solvent hydrogen bond basicity similarly to those established previously for small nonionic organic compounds. (C) 2011 Elsevier B.V. All rights reserved.
palavras-chave
SOLVATOCHROMIC COMPARISON METHOD; SOLVATION ENERGY RELATIONSHIPS; BIPHASIC SYSTEMS; POLYETHYLENE-GLYCOL; ORGANIC-MOLECULES; METHYLENE GROUP; HYDROGEN-BONDS; PI-STAR; WATER; HYDROPHOBICITY
categoria
Biochemistry & Molecular Biology; Chemistry
autores
Madeira, PP; Reis, CA; Rodrigues, AE; Mikheeva, LM; Chait, A; Zaslavsky, BY
nossos autores
Pedro António Palma Madeira
Investigador Júnioragradecimentos
P.P.M. acknowledges the financial support (grant SFRH/BPD/45055/2008) from Fundacao para a Ciencia e a Tecnologia (FCT), Lisbon, Portugal.