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Temperature and salt controlled tuning of protein clusters

Beck, Christian ; Grimaldo, Marco ; Braun, Michal K. ; Bühl, Lena ; Matsarskaia, Olga ; Jalarvo, Niina H. ; Zhang, Fajun ; Roosen-Runge, Felix LU ; Schreiber, Frank and Seydel, Tilo (2021) In Soft Matter 17(37). p.8506-8516
Abstract

The formation of molecular assemblies in protein solutions is of strong interest both from a fundamental viewpoint and for biomedical applications. While ordered and desired protein assemblies are indispensable for some biological functions, undesired protein condensation can induce serious diseases. As a common cofactor, the presence of salt ions is essential for some biological processes involving proteins, and in aqueous suspensions of proteins can also give rise to complex phase diagrams including homogeneous solutions, large aggregates, and dissolution regimes. Here, we systematically study the cluster formation approaching the phase separation in aqueous solutions of the globular protein BSA as a function of temperature (T), the... (More)

The formation of molecular assemblies in protein solutions is of strong interest both from a fundamental viewpoint and for biomedical applications. While ordered and desired protein assemblies are indispensable for some biological functions, undesired protein condensation can induce serious diseases. As a common cofactor, the presence of salt ions is essential for some biological processes involving proteins, and in aqueous suspensions of proteins can also give rise to complex phase diagrams including homogeneous solutions, large aggregates, and dissolution regimes. Here, we systematically study the cluster formation approaching the phase separation in aqueous solutions of the globular protein BSA as a function of temperature (T), the protein concentration (cp) and the concentrations of the trivalent salts YCl3and LaCl3(cs). As an important complement to structural,i.e.time-averaged, techniques we employ a dynamical technique that can detect clusters even when they are transient on the order of a few nanoseconds. By employing incoherent neutron spectroscopy, we unambiguously determine the short-time self-diffusion of the protein clusters depending oncp,csandT. We determine the cluster size in terms of effective hydrodynamic radii as manifested by the cluster center-of-mass diffusion coefficientsD. For both salts, we find a simple functional formD(cp,cs,T) in the parameter range explored. The calculated inter-particle attraction strength, determined from the microscopic and short-time diffusive properties of the samples, increases with salt concentration and temperature in the regime investigated and can be linked to the macroscopic behavior of the samples.

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author
; ; ; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Soft Matter
volume
17
issue
37
pages
11 pages
publisher
Royal Society of Chemistry
external identifiers
  • pmid:34490428
  • scopus:85116463913
ISSN
1744-683X
DOI
10.1039/d1sm00418b
language
English
LU publication?
yes
additional info
Publisher Copyright: © The Royal Society of Chemistry 2021.
id
1624fe2f-7a90-4617-8a15-b19119a1e3ab
date added to LUP
2021-10-22 10:45:23
date last changed
2024-03-23 12:03:21
@article{1624fe2f-7a90-4617-8a15-b19119a1e3ab,
  abstract     = {{<p>The formation of molecular assemblies in protein solutions is of strong interest both from a fundamental viewpoint and for biomedical applications. While ordered and desired protein assemblies are indispensable for some biological functions, undesired protein condensation can induce serious diseases. As a common cofactor, the presence of salt ions is essential for some biological processes involving proteins, and in aqueous suspensions of proteins can also give rise to complex phase diagrams including homogeneous solutions, large aggregates, and dissolution regimes. Here, we systematically study the cluster formation approaching the phase separation in aqueous solutions of the globular protein BSA as a function of temperature (T), the protein concentration (c<sub>p</sub>) and the concentrations of the trivalent salts YCl<sub>3</sub>and LaCl<sub>3</sub>(c<sub>s</sub>). As an important complement to structural,i.e.time-averaged, techniques we employ a dynamical technique that can detect clusters even when they are transient on the order of a few nanoseconds. By employing incoherent neutron spectroscopy, we unambiguously determine the short-time self-diffusion of the protein clusters depending onc<sub>p</sub>,c<sub>s</sub>andT. We determine the cluster size in terms of effective hydrodynamic radii as manifested by the cluster center-of-mass diffusion coefficientsD. For both salts, we find a simple functional formD(c<sub>p</sub>,c<sub>s</sub>,T) in the parameter range explored. The calculated inter-particle attraction strength, determined from the microscopic and short-time diffusive properties of the samples, increases with salt concentration and temperature in the regime investigated and can be linked to the macroscopic behavior of the samples.</p>}},
  author       = {{Beck, Christian and Grimaldo, Marco and Braun, Michal K. and Bühl, Lena and Matsarskaia, Olga and Jalarvo, Niina H. and Zhang, Fajun and Roosen-Runge, Felix and Schreiber, Frank and Seydel, Tilo}},
  issn         = {{1744-683X}},
  language     = {{eng}},
  month        = {{10}},
  number       = {{37}},
  pages        = {{8506--8516}},
  publisher    = {{Royal Society of Chemistry}},
  series       = {{Soft Matter}},
  title        = {{Temperature and salt controlled tuning of protein clusters}},
  url          = {{http://dx.doi.org/10.1039/d1sm00418b}},
  doi          = {{10.1039/d1sm00418b}},
  volume       = {{17}},
  year         = {{2021}},
}