The European Physical Journal E

, Volume 32, Issue 4, pp 399–409

Molecular dynamics simulations of cytochrome c unfolding in AOT reverse micelles: The first steps

Regular Article

DOI: 10.1140/epje/i2010-10635-x

Cite this article as:
Abel, S., Waks, M. & Marchi, M. Eur. Phys. J. E (2010) 32: 399. doi:10.1140/epje/i2010-10635-x

Abstract.

This paper explores the reduced form of horse cytochrome c confined in reverse micelles (RM) of sodium bis-(2-ethylhexyl) sulfosuccinate (AOT) in isooctane by molecular dynamics simulation. RMs of two sizes were constructed at a water content of Wo = [ H_2O ]/[AOT] = 5.5 and 9.1. Our results show that the protein secondary structure and the heme conformation both depend on micellar hydration. At low hydration, the protein structure and the heme moiety remain stable, whereas at high water content the protein becomes unstable and starts to unfold. At Wo = 9.1 , according to the X-ray structure, conformational changes are mainly localized on protein loops and around the heme moiety, where we observe a partial opening of the heme crevice. These findings suggest that within our time window (10ns), the structural changes observed at the heme level are the first steps of the protein denaturation process, previously described experimentally in micellar solutions. In addition, a specific binding of AOT molecules to a few lysine residues of the protein was found only in the small-sized RM.

Copyright information

© EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2010

Authors and Affiliations

  1. 1.Commissariat à l’Energie Atomique, DSV/iBiTecS/SB2SM, CNRS URA2096Gif-sur-YvetteFrance
  2. 2.Laboratoire Imagerie ParamétriqueUPMCParisFrance
  3. 3.CNRS, LIP UMR7623ParisFrance

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