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Viscosity and diffusion : Crowding and salt effects in protein solutions

Heinen, Marco ; Zanini, Fabio ; Roosen-Runge, Felix LU ; Fedunová, Diana ; Zhang, Fajun ; Hennig, Marcus ; Seydel, Tilo ; Schweins, Ralf ; Sztucki, Michael and Antalík, Marián , et al. (2012) In Soft Matter 8(5). p.1404-1419
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... (More)

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.

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publishing date
type
Contribution to journal
publication status
published
in
Soft Matter
volume
8
issue
5
pages
16 pages
publisher
Royal Society of Chemistry
external identifiers
  • scopus:84862926002
ISSN
1744-683X
DOI
10.1039/c1sm06242e
language
English
LU publication?
no
id
f436c884-d593-4d65-a91b-578573b0385a
date added to LUP
2018-12-17 09:52:54
date last changed
2022-04-10 04:37:16
@article{f436c884-d593-4d65-a91b-578573b0385a,
  abstract     = {{<p>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.</p>}},
  author       = {{Heinen, Marco and Zanini, Fabio and Roosen-Runge, Felix and Fedunová, Diana and Zhang, Fajun and Hennig, Marcus and Seydel, Tilo and Schweins, Ralf and Sztucki, Michael and Antalík, Marián and Schreiber, Frank and Nägele, Gerhard}},
  issn         = {{1744-683X}},
  language     = {{eng}},
  month        = {{02}},
  number       = {{5}},
  pages        = {{1404--1419}},
  publisher    = {{Royal Society of Chemistry}},
  series       = {{Soft Matter}},
  title        = {{Viscosity and diffusion : Crowding and salt effects in protein solutions}},
  url          = {{http://dx.doi.org/10.1039/c1sm06242e}},
  doi          = {{10.1039/c1sm06242e}},
  volume       = {{8}},
  year         = {{2012}},
}