Journal Article

PreJuSER-17773

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Viscosity and diffusion: crowding and salt effects in protein solutions

Heinen, M.FZJ* ; Zanini, F. ; Roosen-Runge, F. ; Fedunová, D. ; Zhang, F. ; Hennig, M. ; Seydel, T. ; Schweins, R. ; Sztucki, M. ; Antalik, M. ; Schreiber, F. ; Nägele, G.FZJ*

2012
Royal Society of Chemistry (RSC) Cambridge

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Please use a persistent id in citations: http://hdl.handle.net/2128/4632  doi:10.1039/c1sm06242e

Abstract: We report on a joint experimental–theoretical study of collective diffusion in, and static shear viscosity of solutions of bovine serum albumin (BSA) proteins, focusing on the dependence on protein and salt concentration. Data obtained from dynamic light scattering and rheometric measurements are compared to theoretical calculations based on an analytically treatable spheroid model of BSA with isotropic screened Coulomb plus hard-sphere interactions. The only input to the dynamics calculations is the static structure factor obtained from a consistent theoretical fit to a concentration series of small-angle X-ray scattering (SAXS) data. This fit is based on an integral equation scheme that combines high accuracy with low computational cost. All experimentally probed dynamic and static properties are reproduced theoretically with an at least semi-quantitative accuracy. For lower protein concentration and low salinity, both theory and experiment show a maximum in the reduced viscosity, caused by the electrostatic repulsion of proteins. On employing our theoretical and experimental results, the applicability range of a generalized Stokes–Einstein (GSE) relation connecting viscosity, collective diffusion coefficient, and osmotic compressibility, proposed by Kholodenko and Douglas [Phys. Rev. E, 1995, 51, 1081] is examined. Significant violation of the GSE relation is found, both in experimental data and in theoretical models, in concentrated systems at physiological salinity, and under low-salt conditions for arbitrary protein concentrations.

Note: Record converted from VDB: 12.11.2012

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Contributing Institute(s):

1. Weiche Materie (ICS-3)

Research Program(s):

1. BioSoft: Makromolekulare Systeme und biologische Informationsverarbeitung (P45)

Appears in the scientific report 2012

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Database coverage:
; ; ; Allianz-Lizenz / DFG ; Current Contents - Social and Behavioral Sciences ; JCR ; Nationallizenz ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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