title: Functionalized magnetic carbonaceous microspheres for trypsin immobilization and the application to fast proteolysis.
abstract: In this study, magnetic carbonaceous (MC) microspheres prepared with a large-scale synthesis approach were developed as the novel substrate for enzyme immobilization, and the trypsin-immobilized MC microspheres were successfully applied to protein fast digestion. Firstly, MC microspheres with small size, strong magnetism, and biological compatibility were prepared through two-step solvothermal reactions. Secondly, MC microsphere surface was modified by 3-glycidoxypropyltrimethoxysilane (GLYMO). Finally, the enzyme was immobilized on the GLYMO-functionalized MC microspheres. The enzyme-immobilized magnetic microspheres were applied for fast protein digestion with microwave-assistance. Bovine serum albumin, myoglobin and cytochrome c, were used as model proteins to verify the digestion efficiency, and the digestion products were then characterized using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) with sequence coverage of 43%, 90% and 77%, respectively. The enzyme-immobilized magnetic particles were also successfully applied to the analysis of human pituitary extract. After database search, 485 proteins (p<0.01) were identified when the extract was digested by the microspheres. This opens a route for its future application in bottom-up proteomic analysis.
authors.affiliation: Department of Chemistry, Fudan University, Shanghai 200433, China.
authors.forename: Guoping
authors.initials: G
authors.lastname: Yao
authors.forename: Dawei
authors.initials: D
authors.lastname: Qi
authors.forename: Chunhui
authors.initials: C
authors.lastname: Deng
authors.forename: Xiangmin
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D002853:Chromatography, Liquid; D006801:Humans; D006868:Hydrolysis; D046529:Microscopy, Electron, Transmission; D008863:Microspheres; D008872:Microwaves; D008969:Molecular Sequence Data; D011506:Proteins / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D014357:Trypsin / Q000737:chemistry*
chemical_list: D011506:Proteins; D014357:Trypsin