Abstract
Among the family of metalloproteases, matrix metalloproteases constitute a small family of 23 zinc-dependant endopeptidases whose precise role remains the hydrolysis of extracellular matrix compounds. Hit has been emphasized that such enzymes are involved in key biological processes such as inflammatory and immune response or healing process. Besides, clear links have been made between the upregulation of certain MMPs and pathological behaviours, especially regarding inflammatory diseases. Thus, MMPs could be used as potential biomarkers promoting easier pathology profiling, early diagnosis and prognosis. Detection and quantification of active MMPs constitutes a key challenge in proteomics studies. In such context, photoaffinity labeling techniques are currently gold standard strategies, but reach its limits facing the need for in-vivo analysis. Based on the design of a new generation of activity-based probes, we offer the possibility to promote identification and quantification of active MMP-12, overexpressed in atherosclerosis and chronic pulmonary diseases, using MALDI-MS technology. As such technology tackles several challenges regarding analysis of complex biological mixtures or faintly abundant protein complexes, MS labelling strategies have been implemented in order to overcome MS issues such as analyte concentration or localization, ionization efficiency or even media complexity. In this way, new probes have been designed to tracelessly and specifically label metalloproteases with a mass tag, promoting selective ionization and signal improvement for the targeted biomolecule. Coupling ABP strategy with the use of an α-cyano-4-hydroxycinnamic acid derivative, in discriminating analytical conditions, enabled the specific detection of MMP-12 labeled fragment, both in biological fluids and tissues, while promoting quantification in fluids using MALDI-MS and localization in tissues using MALDI-MS Imaging.