Figure 1.

Fast-relaxing targeted covalent photoswitch of endogenous GluRs. (A) Schematic representation of the click chemistry strategy adopted for the preparation of TCP ligands. Modular parts are the ligand (red), the photoswitch (blue), and the reactive anchoring group (green). (B) Molecular design showing “head” (1) and “tail” (2) precursors of TCP_fast (3) that are freshly coupled via a copper(I)-catalyzed azide–alkyne cycloaddition prior to incubation in neuronal tissue. (C) Chemical structure and photoisomerization of TCP_fast between the cis (blue light, λ = 460 nm) and trans (dark, fast relaxation) conformations.