Activity-based proteomic profiling (ABPP) employing a serine hydrolase-directed probe to identify changes in activity profiles of lipid hydrolase in lung tumors

Lung tumors, as well as normal tumor-adjacent (NTA) tissue of non-small cell lung cancer (NSCLC) patients, were collected and subjected to labeling with a serine hydrolase-directed activity-based probe (ABP) immediately after excision. Labeling with the serine hydrolase-directed ABP allows for the detection of active lipid hydrolases, which are the focus of our investigation. The labeled proteins (corresponding to active enzymes at time of labeling) were enriched using a biotin-containing linker that was covalently attached using strain-promoted alkyne-azide cycloaddition (click chemistry). Shotgun proteomics of the on-bead digested enriched proteins of ABP-treated and control samples enabled identification of enriched proteins as well as comparison of activity profiles between NTA and tumor samples of NSCLC patients.