title: Quantitative assessment of protein adsorption on microparticles with particle mass spectrometry.
abstract: In this paper, particle mass spectrometry (PMS), which consists of an aerodynamic desorption/ionization (AD) source, a quadrupole ion trap (QIT) mass analyzer, and a charge detector, was exploited to characterize the protein adsorption on microparticles based on the mass variations of microparticles before and after protein adsorption. This method is simple and has low sample cost. Importantly, its mass resolution is good enough to distinguish the microparticles with and without protein. For the adsorption of bovine serum albumin (BSA) on 3 μm porous poly styrene-divinylbenzene (poly S-DVB), the minimum mass increase that can be resolved by PMS corresponds to 128 fg (1.8 ng/cm(2)) or 1.17 × 10(6) BSA molecules on each poly S-DVB particle. With PMS, the adsorption process of BSA on poly S-DVB spheres was successfully characterized, and the obtained maximum adsorption capacity qm and dissociation constant Kd were consistent with that determined by the conventional depletion method. In addition, the influence of surface modification of silica particles on the enzyme immobilization was evaluated. Compared with C4 (propyldimethylsilane), C8 (octyldimethylsilane), and Ph (phenyldimethylchlorosilane), the CN (cyanoethyldimethylchlorosilane) functionalized silica particles were screened to be most beneficial for the immobilization of both lysozyme and trypsin.
authors.affiliation: Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry Chinese Academy of Sciences and Beijing National Laboratory for Molecular Sciences , Beijing 100190, China.
authors.forename: Caiqiao
authors.initials: C
authors.lastname: Xiong
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Zhou
authors.forename: Ning
authors.initials: N
authors.lastname: Zhang
authors.forename: Lingpeng
authors.initials: L
authors.lastname: Zhan
authors.forename: Suming
authors.initials: S
authors.lastname: Chen
authors.forename: Jiyun
authors.initials: J
authors.lastname: Wang
authors.forename: Wen-Ping
authors.initials: WP
authors.lastname: Peng
authors.forename: Huan-Cheng
authors.initials: HC
authors.lastname: Chang
authors.forename: Zongxiu
authors.initials: Z
authors.lastname: Nie
mesh_terms: D000327:Adsorption; D002138:Calibration; D004800:Enzymes, Immobilized / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D013058:Mass Spectrometry; D009113:Muramidase / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D011506:Proteins / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D012822:Silicon Dioxide; D014357:Trypsin / Q000737:chemistry
chemical_list: D004800:Enzymes, Immobilized; D011506:Proteins; D012710:Serum Albumin, Bovine; D012822:Silicon Dioxide; D009113:Muramidase; D014357:Trypsin