title: Enzymatic reaction of the immobilized enzyme on porous silicon studied by matrix-assisted laser desorption/ionization-time of flight-mass spectrometry.
abstract: Desorption/ionization on silicon mass spectrometry (DIOS-MS) is a matrix-free technique that allows for the direct desorption/ionization of low-molecular-weight compounds with little or no fragmentation of analytes. This technique has a relatively high tolerance for contaminants commonly found in biological samples. DIOS-MS has been applied to determine the activity of immobilized enzymes on the porous silicon surface. Enzyme activities were also monitored with the addition of a competitive inhibitor in the substrate solution. It is demonstrated that this method can be applied to the screening of enzyme inhibitors. Furthermore, a method for peptide mapping analysis by in situ digestion of proteins on the porous silicon surface modified by trypsin, combined with matrix-assisted laser desorption/ionization-time of flight-MS has been developed.
authors.affiliation: National Chromatographic R & A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China.
authors.forename: Songyun
authors.initials: S
authors.lastname: Xu
authors.forename: Chensong
authors.initials: C
authors.lastname: Pan
authors.forename: Ligang
authors.initials: L
authors.lastname: Hu
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Zhong
authors.initials: Z
authors.lastname: Guo
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Hanfa
authors.initials: H
authors.lastname: Zou
mesh_terms: D000818:Animals; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004800:Enzymes, Immobilized / Q000378:metabolism*; D010446:Peptide Fragments / Q000032:analysis; D010449:Peptide Mapping / Q000379:methods*; D016062:Porosity; D012825:Silicon; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013499:Surface Properties; D014357:Trypsin / Q000378:metabolism*
chemical_list: D004791:Enzyme Inhibitors; D004800:Enzymes, Immobilized; D010446:Peptide Fragments; D014357:Trypsin; D012825:Silicon