Light-Enabled Identification of the Neuronal Substrates of Alkylphenol Anesthetics

General anesthetics are a critical class of drugs in modern medicine; however, the precise mechanisms by which they cause unconsciousness and unwanted side effects are largely undefined. In order to understand pharmacologic mechanisms of anesthetic action, drug interactions with macromolecular substrates and the subsequent functional consequences must be characterized. Analogs of general anesthetics that function as photolabels have been developed to assist in the identification of molecular targets. One such photolabel, meta-azi-propofol (AziPm), is an analog of the clinically used alkylphenol anesthetic propofol. In this work, AziPm is employed in a variety of experiments that aim to identify molecular substrates of propofol. Two proteins identified as propofol targets are more thoroughly examined: (1) the sirtuin deacetylase SIRT2 and (2) the mitochondrial voltage-dependent anion channel (VDAC). The binding sites of propofol on these proteins, and the in vitro functional consequences of propofol binding, are determined. Also described are the molecular interactions of VDAC with a separate ligand, cholesterol, which shares a binding site with propofol. In addition to molecular studies, a novel in vivo photolabeling technique, called optoanesthesia, that utilizes AziPm is introduced, and the behavioral phenotype induced by optoanesthesia in Xenopus laevis tadpoles is characterized. Finally, optoanesthesia is demonstrated with other ligands, including a photoactive analog of an anthracene anesthetic, and mechanistic insight into the pharmacology of this anthracene is revealed