Divide-and-conquer matrisome protein (DC-MaP) strategy: an optimal approach to proteomic matrisome characterization

Currently, the extracellular matrix (ECM) is considered a pivotal complex meshwork of macromolecules playing a plethora of biomolecular functions in health and disease beyond its commonly known mechanical role. Only by unravelling its composition, we can leverage related tissue engineering and pharmacological efforts. Nevertheless, its unbiased proteomic identification still encounters major limitations mainly due to partial ECM enrichment by precipitation, sequential fractionation using unfriendly mass spectrometry (MS) detergents and resuspension with harsh reagents that need to be entirely removed prior to analysis. These methods can be technically challenging and labor-intensive, which affects the reproducibility of ECM identification and induces protein loss. Here, we present a simple new method applicable to tissue fragments of 10 mg and more. The technique involves a standardized procedure for sample processing with an MS-compatible detergent and combined centrifugation. This two-step protocol eliminates the need for laborious sample clarification and divides our samples into 2 fractions, soluble and insoluble, successively enriched with matrisome-associated (ECM-interacting) and core matrisome (structural ECM) proteins.