TY  - JOUR
AU  - Hansen, Jan
AU  - Uthayakumar, Rajeevann
AU  - Pedersen, Jan Skov
AU  - Egelhaaf, Stefan U.
AU  - Platten, Florian
TI  - Interactions in protein solutions close to liquid–liquid phase separation: ethanol reduces attractions via changes of the dielectric solution properties
JO  - Physical chemistry, chemical physics
VL  - 23
IS  - 39
SN  - 1463-9076
CY  - Cambridge
PB  - RSC Publ.
M1  - FZJ-2021-05929
SP  - 22384 - 22394
PY  - 2021
AB  - Ethanol is a common protein crystallization agent, precipitant, and denaturant, but also alters the dielectric properties of solutions. While ethanol-induced unfolding is largely ascribed to its hydrophobic parts, its effect on protein phase separation and inter-protein interactions remains poorly understood. Here, the effects of ethanol and NaCl on the phase behavior and interactions of protein solutions are studied in terms of the metastable liquid–liquid phase separation (LLPS) and the second virial coefficient B2 using lysozyme solutions. Determination of the phase diagrams shows that the cloud-point temperatures are reduced and raised by the addition of ethanol and salt, respectively. The observed trends can be explained using the extended law of corresponding states as changes of B2. The results for B2 agree quantitatively with those of static light scattering and small-angle X-ray scattering experiments. Furthermore, B2 values calculated based on inter-protein interactions described by the Derjaguin-Landau-Verwey-Overbeek (DLVO) potential and considering the dielectric solution properties and electrostatic screening due to the ethanol and salt content quantitatively agree with the experimentally observed B2 values.
LB  - PUB:(DE-HGF)16
C6  - pmid:34608908
UR  - <Go to ISI:>//WOS:000703642400001
DO  - DOI:10.1039/D1CP03210K
UR  - https://juser.fz-juelich.de/record/904359
ER  -