By Irene Hsiao
In "An activity-dependent proximity ligation platform for spatially resolved quantification of active enzymes in single cells," published 24 Nov 2017 in Nature Communications, postdoc Gang Li, graduate student Jeffrey Montgomery, and professor Raymond Moellering describe a new general chemical proteomic platform they have developed for visualizing enzyme activity in single cells. Using a complement of chemical probes and amplification technologies, Moellering and coworkers investigated the role of serine hydrolases and cysteine proteases in cell lines and ovarian cancer spheroids, clusters of a few hundred cells that bud off a primary tumor. Their method confirmed that these enzymes, which are associated with metastasis, were already active and upregulated in single cells. Activity-dependent proximity ligation (ADPL) shows promise as a platform for elucidating protein activity in living cells and animals for basic and translational applications in biology and medicine.