title: Enzyme inhibitor screening by electrospray mass spectrometry with immobilized enzyme on magnetic silica microspheres.
abstract: In this study, a novel technique for screening inhibitors by electrospray mass spectrometry (ESI-MS) with immobilized enzyme on magnetic microspheres has been demonstrated. First, the model enzyme acetylcholinesterase (AChE) is immobilized onto the 3-glycidoxypropyltrimethoxysilane (GLYMO)-modified magnetic silica microspheres. AChE activity was monitored by biochemical assay that is based on mixing of AChE immobilized microspheres and model substrate acetylcholine, separating and detecting the product through ESI-MS. Stability of the enzyme-immobilized microspheres was investigated. No apparent loss of enzyme activity was observed after fivefold reuse of AChE-immobilized microspheres. The enzyme-immobilized bioassay was used to effectively identify AChE inhibitors among two standard samples, huperzine A and huperzine B, and their source herbal Huperzia serrata, all of which were spiked into the substrate. The inhibition was determined by measuring a decrease of product formation using ESI-MS.
authors.affiliation: Department of Chemistry, Fudan University, Shanghai 200433, China.
authors.forename: Fengli
authors.initials: F
authors.lastname: Hu
authors.forename: Huiying
authors.initials: H
authors.lastname: Zhang
authors.forename: Huaqing
authors.initials: H
authors.lastname: Lin
authors.forename: Chunhui
authors.initials: C
authors.lastname: Deng
authors.forename: Xiangmin
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000110:Acetylcholinesterase / Q000737:chemistry*; D002800:Cholinesterase Inhibitors / Q000737:chemistry*; D004800:Enzymes, Immobilized / Q000737:chemistry*; D008280:Magnetics; D008863:Microspheres; D012822:Silicon Dioxide / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D002800:Cholinesterase Inhibitors; D004800:Enzymes, Immobilized; D012822:Silicon Dioxide; D000110:Acetylcholinesterase