How to minimize dye-induced perturbations while studying biomembrane structure and dynamics: PEG linkers as a rational alternative

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Edouard Mobarak - , Helsinki University Hospital (HUS) (Author)
  • Matti Javanainen - , Helsinki University Hospital (HUS) (Author)
  • Waldemar Kulig - , Helsinki University Hospital (HUS) (Author)
  • Alf Honigmann - , Max Planck Institute of Molecular Cell Biology and Genetics (Author)
  • Erdinc Sezgin - , University of Oxford (Author)
  • Noora Aho - , Helsinki University Hospital (HUS) (Author)
  • Christian Eggeling - , University of Oxford (Author)
  • Tomasz Rog - , Helsinki University Hospital (HUS) (Author)
  • Ilpo Vattulainen - , Helsinki University Hospital (HUS) (Author)

Abstract

Organic dye-tagged lipid analogs are essential for many fluorescence-based investigations of complex membrane structures, especially when using advanced microscopy approaches. However, lipid analogs may interfere with membrane structure and dynamics, and it is not obvious that the properties of lipid analogs would match those of non-labeled host lipids. In this work, we bridged atomistic simulations with super-resolution imaging experiments and biomimetic membranes to assess the performance of commonly used sphingomyelin-based lipid analogs. The objective was to compare, on equal footing, the relative strengths and weaknesses of acyl chain labeling, headgroup labeling, and labeling based on poly-ethyl-glycol (PEG) linkers in determining biomembrane properties. We observed that the most appropriate strategy to minimize dye-induced membrane perturbations and to allow consideration of Brownian-like diffusion in liquid-ordered membrane environments is to decouple the dye from a membrane by a PEG linker attached to a lipid headgroup. Yet, while the use of PEG linkers may sound a rational and even an obvious approach to explore membrane dynamics, the results also suggest that the dyes exploiting PEG linkers interfere with molecular interactions and their dynamics. Overall, the results highlight the great care needed when using fluorescent lipid analogs, in particular accurate controls.

Details

Original languageEnglish
Pages (from-to)2436-2445
Number of pages10
Journal Biochimica et biophysica acta : BBA
Volume1860
Issue number11
Publication statusPublished - Nov 2018
Peer-reviewedYes
Externally publishedYes

External IDs

Scopus 85050121034
ORCID /0000-0003-0475-3790/work/155291297

Keywords

Keywords

  • Diffusion, Fluorescent Dyes/chemistry, Lipid Bilayers/chemistry, Molecular Dynamics Simulation, Phosphatidylcholines/chemistry, Polyethylene Glycols/chemistry