Advanced

Binding of Divalent Cations to Insulin : Capillary Electrophoresis and Molecular Simulations

Duboué-Dijon, Elise; Delcroix, Pauline; Martinez-Seara, Hector; Hladílková, Jana LU ; Coufal, Pavel; Křížek, Tomáš and Jungwirth, Pavel (2018) In Journal of Physical Chemistry B 122(21). p.5640-5648
Abstract

In the present study, we characterize the binding of divalent cations to insulin in aqueous salt solutions by means of capillary electrophoresis and molecular dynamics simulations. The results show a strong pH dependence. At low pH, at which all the carboxylate groups are protonated and the protein has an overall positive charge, all the cations exhibit only weak and rather unspecific interactions with insulin. In contrast, at close to neutral pH, when all the carboxylate groups are deprotonated and negatively charged, the charge-neutralizing effect of magnesium, calcium, and zinc, in particular, on the electrophoretic mobility of insulin is significant. This is also reflected in the results of molecular dynamics simulations showing... (More)

In the present study, we characterize the binding of divalent cations to insulin in aqueous salt solutions by means of capillary electrophoresis and molecular dynamics simulations. The results show a strong pH dependence. At low pH, at which all the carboxylate groups are protonated and the protein has an overall positive charge, all the cations exhibit only weak and rather unspecific interactions with insulin. In contrast, at close to neutral pH, when all the carboxylate groups are deprotonated and negatively charged, the charge-neutralizing effect of magnesium, calcium, and zinc, in particular, on the electrophoretic mobility of insulin is significant. This is also reflected in the results of molecular dynamics simulations showing accumulation of cations at the protein surface, which becomes smaller in magnitude upon effective inclusion of electronic polarization via charge rescaling.

(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
Journal of Physical Chemistry B
volume
122
issue
21
pages
9 pages
publisher
The American Chemical Society
external identifiers
  • scopus:85047989464
ISSN
1520-6106
DOI
language
English
LU publication?
yes
id
7b780d7c-dc81-4325-a3c8-ba7515b44a18
date added to LUP
2018-06-12 14:18:47
date last changed
2018-06-13 03:00:04
@article{7b780d7c-dc81-4325-a3c8-ba7515b44a18,
  abstract     = {<p>In the present study, we characterize the binding of divalent cations to insulin in aqueous salt solutions by means of capillary electrophoresis and molecular dynamics simulations. The results show a strong pH dependence. At low pH, at which all the carboxylate groups are protonated and the protein has an overall positive charge, all the cations exhibit only weak and rather unspecific interactions with insulin. In contrast, at close to neutral pH, when all the carboxylate groups are deprotonated and negatively charged, the charge-neutralizing effect of magnesium, calcium, and zinc, in particular, on the electrophoretic mobility of insulin is significant. This is also reflected in the results of molecular dynamics simulations showing accumulation of cations at the protein surface, which becomes smaller in magnitude upon effective inclusion of electronic polarization via charge rescaling.</p>},
  author       = {Duboué-Dijon, Elise and Delcroix, Pauline and Martinez-Seara, Hector and Hladílková, Jana and Coufal, Pavel and Křížek, Tomáš and Jungwirth, Pavel},
  issn         = {1520-6106},
  language     = {eng},
  month        = {05},
  number       = {21},
  pages        = {5640--5648},
  publisher    = {The American Chemical Society},
  series       = {Journal of Physical Chemistry B},
  title        = {Binding of Divalent Cations to Insulin : Capillary Electrophoresis and Molecular Simulations},
  url          = {http://dx.doi.org/},
  volume       = {122},
  year         = {2018},
}