Diphenylhexatriene membrane probes DPH and TMA-DPH: A comparative molecular 
dynamics simulation study

Canto, António M.T.M. do; Robalo, João R.; Santos, Patrícia D.; Carvalho, Alfredo J. Palace; Ramalho, J.P. Prates; Loura, Luís M.S.

doi:10.1016/j.bbamem.2016.07.013

Item

ITEM ACTIONSEXPORT

Add to Basket

Please note that a newer version of this item is available:
https://pure.mpg.de/pubman/item/item_2326598_8

DetailsSummary

Released

Journal Article

Diphenylhexatriene membrane probes DPH and TMA-DPH: A comparative molecular dynamics simulation study

MPS-Authors

/persons/resource/persons185262

Robalo, João R.
Ana Vila Verde, Theorie & Bio-Systeme, Max Planck Institute of Colloids and Interfaces, Max Planck Society;

External Resource

No external resources are shared

Fulltext (restricted access)

There are currently no full texts shared for your IP range.

Fulltext (public)

There are no public fulltexts stored in PuRe

Supplementary Material (public)

There is no public supplementary material available

Citation

Canto, A. M. d., Robalo, J. R., Santos, P. D., Carvalho, A. J. P., Ramalho, J. P., & Loura, L. M. (2016). Diphenylhexatriene membrane probes DPH and TMA-DPH: A comparative molecular dynamics simulation study. Biochimica et Biophysica Acta - Biomembranes, 1858(11), 2647-2661. doi:10.1016/j.bbamem.2016.07.013.

Cite as: https://hdl.handle.net/11858/00-001M-0000-002B-19F0-7

Abstract

Fluorescence spectroscopy and microscopy have been utilized as tools in membrane biophysics for decades now. Because phospholipids are non-fluorescent, the use of extrinsic membrane probes in this context is commonplace. Among the latter, 1,6-diphenylhexatriene (DPH) and its trimethylammonium derivative (TMA-DPH) have been extensively used. It is widely believed that, owing to its additional charged group, TMA-DPH is anchored at the lipid/water interface and reports on a bilayer region that is distinct from that of the hydrophobic DPH. In this study, we employ atomistic MD simulations to characterize the behavior of DPH and TMA-DPH in 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and POPC/cholesterol (4:1) bilayers. We show that although the dynamics of TMA-DPH in these membranes is noticeably more hindered than that of DPH, the location of the average fluorophore of TMA-DPH is only ~ 3–4 Å more shallow than that of DPH. The hindrance observed in the translational and rotational motions of TMA-DPH compared to DPH is mainly not due to significant differences in depth, but to the favorable electrostatic interactions of the former with electronegative lipid atoms instead. By revealing detailed insights on the behavior of these two probes, our results are useful both in the interpretation of past work and in the planning of future experiments using them as membrane reporters.