Analyzing the effects of protecting osmolytes on solute-water interactions by solvatochromic comparison method: II. Globular proteins

authors	Ferreira, LA; Fan, X; Madeira, PP; Kurgan, L; Uversky, VN; Zaslavsky, BY
nationality	International
journal	RSC ADVANCES
keywords	AQUEOUS 2-PHASE SYSTEMS; TRIMETHYLAMINE-N-OXIDE; PREFERENTIAL INTERACTIONS; SOLVENT INTERACTIONS; ELASMOBRANCH FISHES; UNFOLDED PROTEINS; AMINO-ACIDS; STABILIZATION; PREDICTION; MECHANISM
abstract	Partitioning of 11 globular proteins was examined in aqueous dextran-PEG-sodium/potassium phosphate buffer (0.01 M K/NaPB, pH 7.4) two-phase systems (ATPSs) containing 0.5 M sorbitol. The data obtained were analyzed together with those reported previously for the same proteins in osmolyte-free ATPS and ATPS containing 0.5 M sucrose, TMAO, or trehalose. It was found that all the partition coefficients for proteins determined in the presence of 0.5 M of different osmolytes and in the absence of osmolytes may be described in terms of the differences between solvent properties of the coexisting phases. Solute-specific coefficients characterizing different types of solute-solvent interactions were calculated for each protein. These solute-specific coefficients are linearly interrelated implying cooperativity of different types of protein-water interactions. The data obtained indicate the lack of any association of the aforementioned osmolytes at concentration of 0.5 M with proteins. Computational analysis of one of the solute-specific coefficient Ss-values characterizing dipole-dipole protein-water interactions shows that it is determined by the peculiarities of protein surface.
publisher	ROYAL SOC CHEMISTRY
issn	2046-2069
year published	2015
volume	5
issue	73
beginning page	59780
ending page	59791
digital object identifier (doi)	10.1039/c5ra08612d
web of science category	Chemistry, Multidisciplinary
subject category	Chemistry
unique article identifier	WOS:000357961800098