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

Research output: Contribution to journalArticle

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 accumulation of cations at the protein surface, which becomes smaller in magnitude upon effective inclusion of electronic polarization via charge rescaling.

Details

Authors
  • Elise Duboué-Dijon
  • Pauline Delcroix
  • Hector Martinez-Seara
  • Jana Hladílková
  • Pavel Coufal
  • Tomáš Křížek
  • Pavel Jungwirth
Organisations
External organisations
  • Charles University in Prague
  • Institute of Organic Chemistry and Biochemistry
  • J. Heyrovský Institute of Physical Chemistry (JHI CAS)
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Physical Chemistry
Original languageEnglish
Pages (from-to)5640-5648
Number of pages9
JournalJournal of Physical Chemistry B
Volume122
Issue number21
StatePublished - 2018 May 31
Peer-reviewedYes