Switchable Solvatochromic Probes for Live-Cell Super-resolution Imaging of Plasma Membrane Organization

Dmytro Danylchuk (1) , Seonah Moon , Ke Xu , Andrey Klymchenko (2, 2)

1 LBP - Laboratoire de Bioimagerie et Pathologies
2 LBP - Laboratoire de Biophotonique et Pharmacologie - UMR 7213

Visualization of the nanoscale organization of cell membranes remains challenging because of the lack of appropriate fluorescent probes. Here, we introduce a new design concept for super-resolution microscopy probes that combines specific membrane targeting, ON/OFF switching, and environment sensing functions. In this design, we propose a functionalization strategy for solvatochromic dye Nile Red that improves its photostability. The dye is grafted to a newly developed membrane-targeting moiety composed of a sulfonate group and an alkyl chain of varied lengths, which ensures high brightness and lipid-order sensitivity of the probes and tunes their binding/unbinding-induced ON/OFF switching required for single-molecule localization microscopy. While the longchain probe with strong membrane binding, NR12A, is suitable for conventional microscopy, the short-chain probe NR4A, due to the reversible binding, enables first nanoscale cartography of the lipid order exclusively at the surface of live cells. The latter probe reveals in plasma membranes the presence of nanoscopic protrusions and invaginations of lower lipid order, suggesting a subtle connection between membrane morphology and lipid organization.

Domaines: Autre

Dmytro Danylchuk, Seonah Moon, Ke Xu, Andrey Klymchenko. Switchable Solvatochromic Probes for Live-Cell Super-resolution Imaging of Plasma Membrane Organization. Angewandte Chemie International Edition, 2019, 58 (42), pp.14920-14924. ⟨10.1002/anie.201907690⟩. ⟨hal-02379911⟩