Mining Cellular Pyrroloquinoline Quinone Binding Proteins with a Chemoproteomics Strategy

• Applicant: Dr. Tao Wang
• Subject Area: Biological and Biomimetic Chemistry ; Biochemistry
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 515843640

PQQ is an important cofactor for bacteria and humans but much less is known about its function compared to other cofactors. A general method to specifically discover PQQ-binding proteins in live cells has yet to be reported, but would greatly contribute to the understanding of PQQ transportation, regulation and metabolism. In this project, I propose a universal method for mining PQQ-dependent enzymes, including the design of 7 different PQQ-probes functionalized with photocrosslinkers at different sites to enhance the potential of binding proteins in S. typhimurium and human HepG2 cells. PQQ-dependent enzymes will then be comprehensively labeled with a chemoproteomics workflow and identified by quantitative mass spectrometry. Previously uncharacterized PQQ-binding proteins will be validated by enzymatic assays and crystallization to identify their binding pockets. This global profiling strategy represents an innovative breakthrough as there are no current methods for PQQ-ome mining. This technology aims to elucidate PQQ not only as a cofactor in bacteria and human cells but also to provide access to novel antibiotic drug targets as well as highlight desired/undesired binding to human proteins, respectively.

• DFG Programme: WBP Position