Dresden 2017 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 18: Poster: Colloids and Complex Fluids

CPP 18.9: Poster

Monday, March 20, 2017, 18:30–21:00, P1C

Cosolvent Effects on Protein Phase Behavior — •Jan Hansen, Florian Platten, and Stefan U. Egelhaaf — Heinrich Heine University, Condensed Matter Physics Laboratory, Duesseldorf, Germany

Cosolvents are routinely used to modulate the stability of proteins. Yet, they also alter protein--protein interactions, which we characterize by static light scattering and in terms of the macroscopic phase behavior of protein solutions. In particular, we experimentally determined the crystallization boundary, the metastable gas--liquid binodal and the second virial coefficient of lysozyme solutions in the presence of various additives, such as sodium chloride (NaCl), guanidine hydrochloride (GuHCl), and glycerol. Our data indicate that the additives might affect the protein phase behavior through electrostatic screening and additive-specific contributions. NaCl induces attractions, glycerol and GuHCl weaken attractions and/or induce repulsions. Using a two-state thermodynamic model, the cosolvent-dependent changes of the phase boundaries can be related to the respective changes of the free energy.

Hansen et al., PCCP, 2016, 18, 10270.