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

J Mass Spectrom. 2018 Aug;53(8):675-679. doi: 10.1002/jms.4203.

Abstract

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.

Keywords: MALDI-MS; lipophilic peptides; n-laurylmaltoside; n-octylglucoside; nonionic detergents; on-plate digestion; trypsin activity.

MeSH terms

  • Crystallization
  • Enzyme Activation
  • Glucosides / chemistry*
  • Lipopeptides / analysis*
  • Oxidation-Reduction
  • Proteolysis
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / methods*
  • Trypsin / chemistry*

Substances

  • Glucosides
  • Lipopeptides
  • octyl-beta-D-glucoside
  • dodecyl maltoside
  • Trypsin