Caprotec Bioanalytics GmbH View Institution's Website 1 article published in JoVE Biology Profiling of Methyltransferases and Other S-adenosyl-L-homocysteine-binding Proteins by Capture Compound Mass Spectrometry (CCMS) Thomas Lenz1, Peter Poot2, Olivia Gräbner1, Mirko Glinski1, Elmar Weinhold2, Mathias Dreger1, Hubert Köster1 1Department of Biochemistry / Analytics, caprotec bioanalytics GmbH, 2Institute of Organic Chemistry, RWTH Aachen University Capture Compounds are trifunctional small molecules to reduce the complexity of the proteome by functional reversible small molecule-protein interaction followed by photo-crosslinking and purification. Here we use a Capture Compound with S-adenosyl-L-homocysteine-binding as selectivity function to isolate methyltransferases from an Escherichia coli whole cell lysate and identify them by MS.