Giving an Enzyme Scissors: Serotonin Derivatives as Potent Organocatalytic Switches for DNA Repair Enzyme OGG1

: The base excision repair enzyme 8-oxoguanine DNA glycosylase 1 (OGG1) plays a central role in maintaining genome integrity and mediating cellular responses to oxidative stress. As such, it represents an attractive target for pharmaceutical modulation. Small-molecule organocatalytic switches (ORCAs) greatly enhance the rate of OGG1-catalyzed cleavage of DNA abasic sites, thereby accelerating DNA repair. Here, we present the discovery and hit-to-lead optimization of a novel class of highly potent serotonin-derived ORCAs with greatly improved pharmacokinetic properties. Biochemical assays, X-ray crystallography, and molecular dynamics simulations point toward a water-mediated mechanism of activation, distinct from previously proposed Brønsted base-assisted models. These findings establish serotonin-based ORCAs as promising chemical probes and potential leads for therapeutic modulation of OGG1 in oxidative stress-driven diseases.