Displaying the active proteome
To monitor the manipulation of host enzymes during infection, we exploit activity-based protein profiling (ABPP). ABPP is based on the use of small molecule probes that react with the active sites of enzymes in an activity-dependent manner. Labeling is covalent and irreversible and this facilitates the display of labeled proteins on protein gels and the identification of the labeled proteins by mass spectrometry. There are hundreds of probes reported for different enzyme families. We validate these probes and develops novel probes to extend the range of enzymes we can monitor. Our pioneering work introducing ABPP in plant science has resulted in a large and unique probe library and extensive knowledge on enzyme profiling. With probes for cysteine, serine and metallo proteases, the proteasome, lipases, esterases, glycosidases and ATP binding proteins, we have build a powerful platform for international collaborations by hosting visiting scientists. The second aim of our research program is to extend ABPP into plant science by improving quantitative analysis and extending the range of enzymes. Validated probes are used to study apoplast manipulation during infection. Other applications of ABPP beyond our research field are achieved with external collaborators.