Molecular dynamics simulation of dipalmitoylphosphatidylcholine modified with a MTSL nitroxide spin label in a lipid membrane

Sabrina Kemmerer, John C Voss, Roland Faller

Research output: Contribution to journalArticle

5 Scopus citations

Abstract

We investigate the interaction between dipalmitoylphosphatidylcholine (DPPC) and a nitroxide spin label in order to understand its influences on lipid structure and dynamics using molecular dynamics simulations. The system was modified by covalently attaching nitroxide spin labels to the headgroups of two DPPC molecules. (S-(2,2,5,5-tetramethyl-2,5-dihydro-1H-pyrrol-3-yl)methyl methanesulfonothioate) (MTSL) was used as the spin label. The label position and dynamics were analyzed as was the impact of the modified DPPC on the structure of the surrounding lipids. The modified DPPC molecules locate closer to the center of the membrane than unmodified DPPC molecules. The rotation of the spin label is unrestricted, but there are favored orientations. MTSL depresses the deuterium order parameters of the carbon atoms close to the headgroup in surrounding DPPC molecules. The spin label has no impact on order parameters of carbon atoms at the end of the lipid tails. The lateral diffusion constant of the modified DPPC is indistinguishable from unmodified DPPC molecules. These novel computational results suggest an experimental validation.

Original languageEnglish (US)
Pages (from-to)2770-2777
Number of pages8
JournalBiochimica et Biophysica Acta - Biomembranes
Volume1828
Issue number11
DOIs
StatePublished - 2013

Keywords

  • DPPC
  • ESR
  • Molecular dynamics
  • Spin marker

ASJC Scopus subject areas

  • Biochemistry
  • Cell Biology
  • Biophysics

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