UCSF

Enzyme function is ubiquitous in living organisms. Assays and biomarkers utilizing enzyme activity have become a pillar of chemical biology with relevance to the discovery of new biology, clinical diagnostics, and streamlining research and industrial pipelines. This thesis project seeks to develop assays and probes harnessing enzyme activity to expand the current repertoire of biomarkers and inhibitory drugs.Chapter1 describes restricted interaction peptides (RIPs) as a platform technology for tracking protease activity in vivo in real time. We show the proof of concept for this, as we harness the catalytic activity of proteases for tracking various biological events and disease states. This chapter evinces the most characterized and furthest along adaptation of the RIP technology, tracking immune activation via imaging with positron emission tomography (PET) by harnessing granzyme B (GZMB) catalysis Chapter 2 continues the concept of harnessing enzyme activity to aid the field of nuclear medicine and radioimaging by detailing the development of a lipoic acid ligase that conjugates radiofluorine onto proteins of interest that contain a specific peptide substrate sequence. This approach would potentially expand the toolbox and broaden the pipelines of proteins amenable to radioimaging. Chapter 3 describes the inhibition, as opposed to the amplification, of enzyme activity by developing substrates and enzyme functional assays for screening inhibitory drugs against the SARS-CoV-2 major protease (Mpro).