A Disintegrin and Metalloproteinase 10 (ADAM10) and ADAM17 catalyze ectodomain shedding of a number of cell surface proteins important for embryonic development and tissue homeostasis. Changes in the expression levels or dysregulated proteolytic activity of ADAM10 and ADAM17 have been shown to play important roles in multiple diseases such as inflammation, cancer, and neurodegenerative disorders. Despite the well documented substrate repertoire of ADAM10 and ADAM17, little is known about their cleavage site specificity. We optimized Q-PICS (Quantitative Proteomics for the Identification of Cleavage Sites) to elucidate the cleavage site specificity of recombinant murine ADAM10 and ADAM17. Two different yeast proteome-derived peptide libraries were used and samples were analyzed by LC-MALDI and LC-ESI MS in parallel. We show that the largest difference in the cleavage site specificities of ADAM10 and ADAM17 is at the P1' site: while both enzymes cleave N-terminal of leucine, only ADAM10 shows additional preference toward aromatic amino acids, whereas ADAM17 exhibits the highest preference for valine. Together with further amino acid preferences more adjacent to the scissile bond, our data is in good agreement with ADAM10/17 cleavage sites previously identified in native substrates. Overall, the precise identification of ADAM10 and ADAM17 cleavage site specificity provides the basis for better substrate identification in vivo and the generation of specific inhibitors or activity based probes.

No abstract

No abstract

No abstract

The determination of a protease's cleavage site specificity is one of the major goals in degradomics. In the last years, the use of proteome-derived peptide libraries and liquid chromatography-mass spectrometry (LC-MS) in a proteomic identification of protease cleavage sites (PICS) experiment became popular for that purpose.In this chapter, we offer a step-by-step protocol for the execution of a quantitative proteomic identification of protease cleavage sites (Q-PICS) experiment, which enables the relative quantification of proteolytic events by isobaric labeling, e.g., with tandem mass tags (TMT). In this way, the cleavage site specificity and activity of a protease can be compared under different reaction conditions (e.g., buffer, pH, temperature, inhibitor). Multiplexing can further be used to analyze replicate experiments in parallel, decreasing instrument times and work effort significantly, or to perform internal controls.