Detergent‐assisted sample preparation for MALDI‐MS: Investigation of octylglucoside and docecylmaltoside for matrix crystallization,on‐plate digestion,and trypsin activity

We show an easy and fast method for improved detection of lipophilic peptides with MALDI‐MS utilizing the nonionic detergents n‐octylglucoside and n‐dodecylmaltoside (laurylmaltoside). Investigations comprised on‐plate digestion of proteins with trypsin, detergent effects on the protease trypsin, and the changes in MALDI matrix crystallization. Investigations also exhibited a higher tryptic activity in trypsin activity assay of 139% when using laurylmaltoside as supplement. Crystallization changed toward a more homogeneous crystal distribution and especially trypsinized insulin spectra recorded with MALDI‐MS showed improved detectability of lipophilic peptides.