In this work, a membrane probe (NR18) with a Nile Red-based chromophore, a long tail of 18 carbon atoms and a zwitterionic head was synthesized. The probe is optimized to remain anchored to the phospholipid bilayer without internalizing. NR18 was fully characterized chemically and optically and showed marked solvatochromism. Incorporation into model membranes of LUVs and GUVs having different compositions, demonstrated that the probe could be used to discriminate the lipid order in membranes, based on the fluorescent radiation emitted. Spectrophotometric and fluorimetric measurements on LUVs showed that the emission wavelength increases with temperature, confirming the increase in fluidity and hydration in membranes at higher temperatures. DFT simulations helped us to clarify the impact of NR18 on the membrane thickness and the order parameter showing that NR18 does not cause substantial perturbation in the bilayer. Moreover, we demonstrated that the presence of an enaminic terminal group is mainly responsible for the ability of NR18 to have a different fluorescence in Ld and Lo membranes.

A selective Nile Red based solvatochromic probe: A study of fluorescence in LUVs and GUVs model membranes

Sessa L.
Writing – Original Draft Preparation
;
Concilio S.
Writing – Review & Editing
;
Di Martino M.
Investigation
;
Nardiello A. M.
Data Curation
;
Miele Y.
Investigation
;
Piotto S.
Funding Acquisition
2021

Abstract

In this work, a membrane probe (NR18) with a Nile Red-based chromophore, a long tail of 18 carbon atoms and a zwitterionic head was synthesized. The probe is optimized to remain anchored to the phospholipid bilayer without internalizing. NR18 was fully characterized chemically and optically and showed marked solvatochromism. Incorporation into model membranes of LUVs and GUVs having different compositions, demonstrated that the probe could be used to discriminate the lipid order in membranes, based on the fluorescent radiation emitted. Spectrophotometric and fluorimetric measurements on LUVs showed that the emission wavelength increases with temperature, confirming the increase in fluidity and hydration in membranes at higher temperatures. DFT simulations helped us to clarify the impact of NR18 on the membrane thickness and the order parameter showing that NR18 does not cause substantial perturbation in the bilayer. Moreover, we demonstrated that the presence of an enaminic terminal group is mainly responsible for the ability of NR18 to have a different fluorescence in Ld and Lo membranes.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11386/4769911
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 1
  • ???jsp.display-item.citation.isi??? ND
social impact