Updated project metadata. We attempt to study the interactome of PDEs by synthesizing a broad spectrum PDE-capturing resin based on the non-selective PDE inhibitor 3-isobutyl-1-methylxanthine (IBMX). Chemical proteomics characterization of this resin in HeLa cell lysates led to the capture of several different PDEs. Combining the IBMX-resin with in-solution competition with other available, more selective PDE inhibitors, namely cilostamide and papaverine, allowed us to selectively probe the interactome of PDE3A in HeLa cells.