Advanced

Generic pathways to stability in concentrated protein mixtures

Voets, Ilja K.; Trappe, Veronique and Schurtenberger, Peter LU (2012) In Physical Chemistry Chemical Physics 14(8). p.2929-2933
Abstract
We present a series of experimental results that disclose the crucial role of ionic strength and partial volume fractions in the control of the phase behaviour of binary protein mixtures. Our findings can be understood as that the ionic strength determines the relative contribution of the entropy of the protein counter-ions to the overall thermodynamics of the system. Associative phase separation and crystallization observed at, respectively, low and high ionic strength are suppressed at intermediate salt concentrations, where the entropy gain upon releasing the counter-ions from the double layer of the proteins is negligible and the entropy loss upon confining the counter-ions within the protein crystal phase significant. Moreover, we... (More)
We present a series of experimental results that disclose the crucial role of ionic strength and partial volume fractions in the control of the phase behaviour of binary protein mixtures. Our findings can be understood as that the ionic strength determines the relative contribution of the entropy of the protein counter-ions to the overall thermodynamics of the system. Associative phase separation and crystallization observed at, respectively, low and high ionic strength are suppressed at intermediate salt concentrations, where the entropy gain upon releasing the counter-ions from the double layer of the proteins is negligible and the entropy loss upon confining the counter-ions within the protein crystal phase significant. Moreover, we find that the partial volume fraction of the protein prone to crystallize determines the crystallization boundary and that the presence of other proteins strongly delays crystallization, leading to temporarily stable mixtures. These findings suggest that stability in more complex protein mixtures, such as the cytosol, relates to the ionic strength and protein composition rather than to protein specific properties. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Chemistry Chemical Physics
volume
14
issue
8
pages
2929 - 2933
publisher
Royal Society of Chemistry
external identifiers
  • wos:000299742000045
  • scopus:84856911453
ISSN
1463-9084
DOI
10.1039/c2cp22558a
language
English
LU publication?
yes
id
bad981c8-1f12-414c-be9a-4a616f1216ee (old id 2425545)
date added to LUP
2012-03-23 09:50:46
date last changed
2017-01-01 05:54:40
@article{bad981c8-1f12-414c-be9a-4a616f1216ee,
  abstract     = {We present a series of experimental results that disclose the crucial role of ionic strength and partial volume fractions in the control of the phase behaviour of binary protein mixtures. Our findings can be understood as that the ionic strength determines the relative contribution of the entropy of the protein counter-ions to the overall thermodynamics of the system. Associative phase separation and crystallization observed at, respectively, low and high ionic strength are suppressed at intermediate salt concentrations, where the entropy gain upon releasing the counter-ions from the double layer of the proteins is negligible and the entropy loss upon confining the counter-ions within the protein crystal phase significant. Moreover, we find that the partial volume fraction of the protein prone to crystallize determines the crystallization boundary and that the presence of other proteins strongly delays crystallization, leading to temporarily stable mixtures. These findings suggest that stability in more complex protein mixtures, such as the cytosol, relates to the ionic strength and protein composition rather than to protein specific properties.},
  author       = {Voets, Ilja K. and Trappe, Veronique and Schurtenberger, Peter},
  issn         = {1463-9084},
  language     = {eng},
  number       = {8},
  pages        = {2929--2933},
  publisher    = {Royal Society of Chemistry},
  series       = {Physical Chemistry Chemical Physics},
  title        = {Generic pathways to stability in concentrated protein mixtures},
  url          = {http://dx.doi.org/10.1039/c2cp22558a},
  volume       = {14},
  year         = {2012},
}