Chang Sarah Y, Zheng Nan-Yan, Chen Chee-Shan, Chen Cheng-Dah, Chen Ying-Yi, Wang C R Cris
Department of Chemistry, Tunghai University, Taichung, Taiwan.
J Am Soc Mass Spectrom. 2007 May;18(5):910-8. doi: 10.1016/j.jasms.2007.01.011. Epub 2007 Mar 23.
Iron oxide nanoparticles modified with oleate have been employed for the extraction of peptides and proteins from aqueous solution before matrix-assisted laser desorption/ionization (MALDI) mass spectrometric (MS) analysis. Adsorption of peptides and proteins onto the nanoparticles were mainly through electrostatic attraction and hydrophobic interaction. The analyte-adsorbed iron oxide nanoparticles could be efficiently collected from solution using a magnet. No elution step was needed. With this preconcentration strategy, the lowest detectable concentration of angiotensin I, insulin, and myoglobin in 500 microL of aqueous solution were 0.1 nM, 0.1 nM, and 10.0 nM, respectively. In addition, the nanoparticles could extract the analytes from solution with a high content of salt and surfactant, thus eliminating suppression effect during MALDI MS analysis. This method was successfully applied to concentrate the tryptic digest products of cytochrome c. In addition, the tryptic digestion of cytochrome c can be directly conducted on the iron oxide nanoparticles.
油酸修饰的氧化铁纳米颗粒已被用于在基质辅助激光解吸/电离（MALDI）质谱（MS）分析之前从水溶液中提取肽和蛋白质。肽和蛋白质在纳米颗粒上的吸附主要通过静电吸引和疏水相互作用。使用磁铁可以有效地从溶液中收集吸附了分析物的氧化铁纳米颗粒。无需洗脱步骤。采用这种预浓缩策略，500微升水溶液中血管紧张素I、胰岛素和肌红蛋白的最低可检测浓度分别为0.1纳摩尔、0.1纳摩尔和10.0纳摩尔。此外，纳米颗粒可以从含有高含量盐和表面活性剂的溶液中提取分析物，从而消除MALDI MS分析过程中的抑制效应。该方法成功应用于浓缩细胞色素c的胰蛋白酶消化产物。此外，细胞色素c的胰蛋白酶消化可以直接在氧化铁纳米颗粒上进行。
