UCSF

The study of protein protein-interactions (PPIs) can be approached with many lenses. Interaction networks can be mapped genetically or with proteomic methods. Biophysical characterization of specific partner interactions can clarify molecular mechanism of partner interaction. Screening methods can to identify novel interaction modulators, and site-directed chemical probes can used to demonstrate the importance of protein partner interaction in disease or biology. In this work I begin with an overview of the chemical biology toolbox for targeting non-catalytic cysteines residues. I apply one such tool, disulfide tethering, to two PPIs with the goal of broadening the PPIs which are targetable with covalent chemical probes. I then describe the use of cysteine-reactive molecules in understanding protein ligandability and its connection to protein dynamics. Finally, I study a promiscuous PPI receptor (Mac-1) to understand if inhibitors could be developed for specific ligands. Taken together, these data demonstrate the applicability of cysteine reactivity generally, and disulfide tethering specifically, to the study of PPIs.