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Adsorption of polyelectrolyte-like proteins to silica surfaces and the impact of pH on the response to ionic strength. A Monte Carlo simulation and ellipsometry study

Hyltegren, Kristin LU and Skepö, Marie LU (2017) In Journal of Colloid and Interface Science 494. p.266-273
Abstract

Hypothesis The adsorbed amount of the polyelectrolyte-like protein histatin 5 on a silica surface depends on the pH and the ionic strength of the solution. Interestingly, an increase in ionic strength affects the adsorbed amount differently depending on the pH of the solution, as shown by ellipsometry measurements (Hyltegren, 2016). We have tested the hypothesis that the same (qualitative) trends can be found also from a coarse-grained model that takes all charge–charge interactions into account within the frameworks of Gouy–Chapman and Debye–Hückel theories. Experiments Using the same coarse-grained model as in our previous Monte Carlo study of single protein adsorption (Hyltegren, 2016), simulations of systems with many histatin 5... (More)

Hypothesis The adsorbed amount of the polyelectrolyte-like protein histatin 5 on a silica surface depends on the pH and the ionic strength of the solution. Interestingly, an increase in ionic strength affects the adsorbed amount differently depending on the pH of the solution, as shown by ellipsometry measurements (Hyltegren, 2016). We have tested the hypothesis that the same (qualitative) trends can be found also from a coarse-grained model that takes all charge–charge interactions into account within the frameworks of Gouy–Chapman and Debye–Hückel theories. Experiments Using the same coarse-grained model as in our previous Monte Carlo study of single protein adsorption (Hyltegren, 2016), simulations of systems with many histatin 5 molecules were performed and then compared with ellipsometry measurements. The strength of the short-ranged attractive interaction between the protein and the surface was varied. Findings The coarse-grained model does not qualitatively reproduce the pH-dependence of the experimentally observed trends in adsorbed amount as a function of ionic strength. However, the simulations cast light on the balance between electrostatic attraction between protein and surface and electrostatic repulsion between adsorbed proteins, the deficiencies of the Langmuir isotherm, and the implications of protein charge regulation in concentrated systems.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Adsorption, Charge regulation, Coarse graining, Ellipsometry, Histatin 5, Intrinsically disordered proteins, Monte Carlo simulations, Polyelectrolytes
in
Journal of Colloid and Interface Science
volume
494
pages
8 pages
publisher
Elsevier
external identifiers
  • scopus:85011093339
  • wos:000395496900030
ISSN
0021-9797
DOI
10.1016/j.jcis.2017.01.087
language
English
LU publication?
yes
id
f6fe8d4c-bd87-43af-bdbc-879befefa05c
date added to LUP
2017-02-14 08:25:12
date last changed
2018-01-07 11:49:32
@article{f6fe8d4c-bd87-43af-bdbc-879befefa05c,
  abstract     = {<p>Hypothesis The adsorbed amount of the polyelectrolyte-like protein histatin 5 on a silica surface depends on the pH and the ionic strength of the solution. Interestingly, an increase in ionic strength affects the adsorbed amount differently depending on the pH of the solution, as shown by ellipsometry measurements (Hyltegren, 2016). We have tested the hypothesis that the same (qualitative) trends can be found also from a coarse-grained model that takes all charge–charge interactions into account within the frameworks of Gouy–Chapman and Debye–Hückel theories. Experiments Using the same coarse-grained model as in our previous Monte Carlo study of single protein adsorption (Hyltegren, 2016), simulations of systems with many histatin 5 molecules were performed and then compared with ellipsometry measurements. The strength of the short-ranged attractive interaction between the protein and the surface was varied. Findings The coarse-grained model does not qualitatively reproduce the pH-dependence of the experimentally observed trends in adsorbed amount as a function of ionic strength. However, the simulations cast light on the balance between electrostatic attraction between protein and surface and electrostatic repulsion between adsorbed proteins, the deficiencies of the Langmuir isotherm, and the implications of protein charge regulation in concentrated systems.</p>},
  author       = {Hyltegren, Kristin and Skepö, Marie},
  issn         = {0021-9797},
  keyword      = {Adsorption,Charge regulation,Coarse graining,Ellipsometry,Histatin 5,Intrinsically disordered proteins,Monte Carlo simulations,Polyelectrolytes},
  language     = {eng},
  month        = {05},
  pages        = {266--273},
  publisher    = {Elsevier},
  series       = {Journal of Colloid and Interface Science},
  title        = {Adsorption of polyelectrolyte-like proteins to silica surfaces and the impact of pH on the response to ionic strength. A Monte Carlo simulation and ellipsometry study},
  url          = {http://dx.doi.org/10.1016/j.jcis.2017.01.087},
  volume       = {494},
  year         = {2017},
}