Evidence Hub

Designer Aromatic Cations for Photo-Induced Protein Ligation, Imaging, and Intracellular Labelling at Extended Wavelengths

Saha PC, Solanke PR, Biswas S, Agarwal V, Taylor MT

bioRxiv : the preprint server for biology, 2025

Abstract

Photo-induced protein labelling strategies have become essential tools in chemical biology, but most strategies require high energy wavelengths of light as input to drive reactivity. Recently, we reported a biocompatible method for engaging photo-induced electron transfer to drive protein labelling using biaryl pyridinium salts and, here, we report the design of a series of aromatic cation salts that trigger this process using longer wavelengths of light while maintaining a sterically minimal profile. We achieved this through the systematic study of structure-reactivity relationships of various donor-acceptor pyridinium salts possessing extended conjugation, and these studies revealed the need of a constrained trans-stilbene relationship between the probe's donor and acceptor substituents in order to achieve protein labelling. Probes with chromene-based donor groups in particular showed either robust protein labelling, significant fluorescence quantum yields, or state-dependent photophysical properties; in turn enabling the same probes to be used for both photo-induced protein labelling and wash-free live-cell imaging. We also demonstrate that these enhanced probes possess robust reactivity in complex biological environments through green light-triggered intracellular labelling in live HeLa cells, resulting in the identification of 659 enriched proteins. This series of experiments not only demonstrates the ability of this latest generation of probes to engage in…

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free