A Cleavable Linker Based on the Levulinoyl Ester for Activity-Based Protein Profiling

摘要

Activity-based protein profiling has recently come to the fore as an attractive strategy to disclose enzyme activity in the context of complex biological samples. An activity-based profiling probe (ABP) normally consists of a recognition element targeted at a specific enzyme (family), and is equipped with a reactive group through which the targeted enzymes are covalently and irreversibly modified. A third essential element of ABPs is the affinity/identification tag, which can be either incorporated into the ABP directly or alternatively installed through a bioorthogonal process in so-called two-step activity-based protein profiling strategies. Visualization/identification tags come in several types, including fluorophores and immune epitope tags. The most popular tag in this context is the biotin group. It is relatively small, easy to manipulate, and has strong binding affinity to streptavidin. As a consequence a range of biochemical tools have become available over the decades for either the visualization of biotinylated biomolecules or their pull-down.