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Effective interactions in protein-salt solutions approaching liquid-liquid phase separation

Wolf, Marcell ; Roosen-Runge, Felix LU ; Zhang, Fajun ; Roth, Roland ; Skoda, Maximilian W.A. ; Jacobs, Robert M.J. ; Sztucki, Michael and Schreiber, Frank (2014) In Journal of Molecular Liquids 200(PA). p.20-27
Abstract

We present an experimental study combined with a theoretical discussion of the effective interactions in protein solutions approaching a liquid-liquid phase separation (LLPS) induced by addition of multivalent metal ions. The reduced second virial coefficient, B2/B2HS, is used to describe the interaction and discussed with theoretical predictions for colloidal systems. We have determined the salt and protein partitioning in the two coexisting phases, which provides the isothermal binodal of the LLPS in the (cp, cs) plane. Two sets of samples, away from and at the LLPS binodal were measured by static light scattering (SLS) and small angle X-ray scattering (SAXS) to determine the... (More)

We present an experimental study combined with a theoretical discussion of the effective interactions in protein solutions approaching a liquid-liquid phase separation (LLPS) induced by addition of multivalent metal ions. The reduced second virial coefficient, B2/B2HS, is used to describe the interaction and discussed with theoretical predictions for colloidal systems. We have determined the salt and protein partitioning in the two coexisting phases, which provides the isothermal binodal of the LLPS in the (cp, cs) plane. Two sets of samples, away from and at the LLPS binodal were measured by static light scattering (SLS) and small angle X-ray scattering (SAXS) to determine the second virial coefficient. In all cases, B2/B2HS is negative in the condensed regime, and increases by approaching the upper critical point in the (cp, cs) plane. The results are compared with a simple colloidal model with isotropic short-ranged attraction and a thermodynamic criterion based on the reduced second virial coefficient. We discuss the application of this theoretical prediction to interpret experimental observations.

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author
; ; ; ; ; ; and
publishing date
type
Contribution to journal
publication status
published
keywords
Liquid-liquid phase separation, Protein-protein interaction, Reduced second virial coefficient, SAXS
in
Journal of Molecular Liquids
volume
200
issue
PA
pages
8 pages
publisher
Elsevier
external identifiers
  • scopus:85027950561
ISSN
0167-7322
DOI
10.1016/j.molliq.2014.08.006
language
English
LU publication?
no
id
6f04e950-d97a-44ca-8c09-d7b4b00b5657
date added to LUP
2018-12-17 09:45:55
date last changed
2022-01-31 07:54:53
@article{6f04e950-d97a-44ca-8c09-d7b4b00b5657,
  abstract     = {{<p>We present an experimental study combined with a theoretical discussion of the effective interactions in protein solutions approaching a liquid-liquid phase separation (LLPS) induced by addition of multivalent metal ions. The reduced second virial coefficient, B<sub>2</sub>/B<sub>2</sub><sup>HS</sup>, is used to describe the interaction and discussed with theoretical predictions for colloidal systems. We have determined the salt and protein partitioning in the two coexisting phases, which provides the isothermal binodal of the LLPS in the (c<sub>p</sub>, c<sub>s</sub>) plane. Two sets of samples, away from and at the LLPS binodal were measured by static light scattering (SLS) and small angle X-ray scattering (SAXS) to determine the second virial coefficient. In all cases, B<sub>2</sub>/B<sub>2</sub><sup>HS</sup> is negative in the condensed regime, and increases by approaching the upper critical point in the (c<sub>p</sub>, c<sub>s</sub>) plane. The results are compared with a simple colloidal model with isotropic short-ranged attraction and a thermodynamic criterion based on the reduced second virial coefficient. We discuss the application of this theoretical prediction to interpret experimental observations.</p>}},
  author       = {{Wolf, Marcell and Roosen-Runge, Felix and Zhang, Fajun and Roth, Roland and Skoda, Maximilian W.A. and Jacobs, Robert M.J. and Sztucki, Michael and Schreiber, Frank}},
  issn         = {{0167-7322}},
  keywords     = {{Liquid-liquid phase separation; Protein-protein interaction; Reduced second virial coefficient; SAXS}},
  language     = {{eng}},
  month        = {{01}},
  number       = {{PA}},
  pages        = {{20--27}},
  publisher    = {{Elsevier}},
  series       = {{Journal of Molecular Liquids}},
  title        = {{Effective interactions in protein-salt solutions approaching liquid-liquid phase separation}},
  url          = {{http://dx.doi.org/10.1016/j.molliq.2014.08.006}},
  doi          = {{10.1016/j.molliq.2014.08.006}},
  volume       = {{200}},
  year         = {{2014}},
}