UC Berkeley

Metals are necessary for sustaining life and play essential roles in each aspect of the central dogma of biology (DNA, RNA, and proteins). While many roles of redox-inactive metals in cellular signaling have been extensively characterized, the ability of redox-active transition metals like copper and iron to act as signals has been less explored. As these metals can aberrantly produce reactive oxygen species (ROS)1, most research has considered redox-active transition metals as cofactors sequestered within enzyme active sites, despite the intricate cellular machinery regulating their concentration in exchangeable forms. Recently, new roles for redox-active metals in their exchangeable (or labile) forms have been elucidated; however, visualizing redox-active metals in real-time (with spatial and temporal resolution) and identifying their protein binding partners remain formidable challenges. This dissertation chronicles the design and applications of novel imaging probes and chemoproteomic strategies for probing redox-active metals in biology. This work describes both the first fluorescence resonance energy transfer (FRET) probe for imaging cellular Fe2+ and the first bioluminescence probe for imaging iron in vivo; both probes utilize an adamantyl-endoperoxide as the iron-reactive moiety. Additionally, this work describes new metalloproteomic methods aimed at identifying novel metal-binding proteins. Taken as a whole, this dissertation describes the development and application of new chemical methods for probing redox-active metals in biology by imaging and/or proteomics.