Abstract
General anesthetic photolabels have been instrumental in discovering and confirming protein binding partners and binding sites of these promiscuous ligands. We report the in vivo photoactivation of meta-azipropofol, a potent analog of propofol, in Xenopus laevis tadpoles. Covalent adduction of meta-azipropofol in vivo prolongs the primary pharmacologic effect of general anesthetics in a behavioral phenotype we termed "optoanesthesia." Coupling this behavior with a tritiated probe, we performed unbiased, time-resolved gel proteomics to identify neuronal targets of meta-azipropofol in vivo. We have identified synaptic binding partners, such as synaptosomal-associated protein 25, as well as voltage-dependent anion channels as potential facilitators of the general anesthetic state. Pairing behavioral phenotypes elicited by the activation of efficacious photolabels in vivo with time-resolved proteomics provides a novel approach to investigate molecular mechanisms of general anesthetics.