Design of Peptide Hydroxamate-Based Photoreactive Activity-Based Probes of Zinc-Dependent Metalloproteases

Metalloproteases (ADAMs, MMPs) are multidomain proteins that play key roles in extracellular matrix remodelling and degradation, in cell-cell and cell-matrix interactions and in the proteolytic liberation of membrane-anchored proforms of cytokines and growth factors, the so-called ectodomain shedding. In this work we describe the development of photoactivatable activity-based probes with which active metalloproteases can be visualised. Our probes are based on the succinyl hydroxamate motif and differ in the positioning of the trifluoromethylphenyldiazirine photoreactive group. We demonstrate that directing the photoactivatable group towards the S1' pocket yields activity-based probes more effective than the corresponding probe with the photoactivatable group directed towards the S2' pocket.