title: Enzyme-coupled nanoparticles-assisted laser desorption ionization mass spectrometry for searching for low-mass inhibitors of enzymes in complex mixtures.
abstract: In this report, enzyme-coupled magnetic nanoparticles (EMPs) were shown to be an effective affinity-based tool for finding specific interactions between enzymatic targets and the low-mass molecules in complex mixtures using classic MALDI-TOF apparatus. EMPs used in this work act as nonorganic matrix enabling ionization of small molecules without any interference in the low-mass range (enzyme-coupled nanoparticles-assisted laser desorption ionization MS, ENALDI MS) and simultaneously carry the superficial specific binding sites to capture inhibitors present in a studied mixture. We evaluated ENALDI approach in two complementary variations: 'ion fading' (IF-ENALDI), based on superficial adsorption of inhibitors and 'ion hunting' (IH-ENALDI), based on selective pre-concentration of inhibitors. IF-ENALDI was applied for two sets of enzyme-inhibitor pairs: tyrosinase-glabridin and trypsin-leupeptin and for the real plant sample: Sparrmannia discolor leaf and stem methanol extract. The efficacy of IH-ENALDI was shown for the pair of trypsin-leupeptin. Both ENALDI approaches pose an alternative for bioassay-guided fractionation, the common method for finding inhibitors in the complex mixtures.
authors.affiliation: University of Orléans, CNRS, ICOA, UMR 7311, 45067, Orleans, France, aleksander.salwinski@univ-orleans.fr.
authors.forename: Aleksander
authors.initials: A
authors.lastname: Salwiński
authors.forename: David
authors.initials: D
authors.lastname: Da Silva
authors.forename: Raphaël
authors.initials: R
authors.lastname: Delépée
authors.forename: Benoît
authors.initials: B
authors.lastname: Maunit
mesh_terms: D004791:Enzyme Inhibitors / Q000032:analysis / Q000302:isolation & purification* / Q000378:metabolism; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism; D053758:Nanoparticles / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D004791:Enzyme Inhibitors; D004800:Enzymes, Immobilized; D010936:Plant Extracts