Chemotherapy remains popular despite the incidental reduction in patient quality-of-life from off-target cell killing. Their clinical acceptance stems from high efficacy, but looking forward, targeted chemotherapies are in high demand. Prodrug converting enzymes (PCEs), proteins that can convert harmless prodrugs into cytotoxic compounds, represent one possibility to satisfy this exigence, but they must be engineered to be active only in cells of interest.<br/><br/>Conditional degradation domains, which fate any protein to which they are tethered to proteolysis unless a specific trigger is presented, are therefore a logical choice to maintain low basal levels of PCEs while allowing for rescue from degradation in the presence of cancer. Employing unique cancer proteomic profiles is one possible method to engineer a PCE system to be sensitive to cancer, while destining the PCE to degradation in a healthy cell. Previous work has studied conditional degradation domains responsive to small molecule cues. We expanded upon this work to determine suitable degradation kinetics to provide minimal background activity in the absence of the small molecule while allowing for an increase in PCE-mediated cytotoxicity upon presentation of the cue. We next began to adapt the chemical-triggered protein device to be initiated by E6, an oncoviral protein unique to human papillomavirus (HPV) infected cells, as a model system. To achieve this, we explored the effects of short protein-interaction motifs on the end of a degradation tag, and we probed for changes in proteolysis kinetics as a result of the larger binding partner uniting with its ligand. Future prospects include combined usage of degradation tags in Boolean logic-based protein devices in which multiple cancer inputs are required to result in PCE rescue.

Controlled protein degradation for the conditional survival of cancer suicide enzymes

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.