精氨酸功能化磁性纳米材料的制备及在磷酸化肽富集中的应用

以精氨酸修饰的磁性微球作为磁性固相萃取(MSPE)平台的载体, 结合基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)技术, 实现了对复杂样品中低丰度磷酸化肽的分离富集. 采用场发射扫描电子显微镜、 Zeta电位测定、 红外光谱分析、 振动样品磁强计及X射线衍射分析等手段对合成的功能化磁性材料进行了表征. 选择β-酪蛋白酶解产物磷酸化肽为标准品, 在最佳实验条件下, 利用构建的MSPE-MS平台能够实现对磷酸化肽的高选择性和高灵敏度检测, 检出限为0.1 fmol. 实验结果表明, 经精氨酸修饰的磁性材料对牛奶样品中低含量的磷酸化肽具有较高的选择性, 所建立的方法适用于复杂样品的分离分析.

Arginine Functionalized Magnetic Nanoparticles and Its Application in Phosphopeptides Enrichment

Arginine modified magnetic nanoparticles（Mag-Arg） were synthesized and used as themagnetic carrier of magnetic solid phase extraction（MSPE） platform. The prepared magnetic nanoparticles were applied to the enrichment of phosphopeptides from complex samples coupled with MALDI-TOF MS. Mag-Arg was characterized by means of scanning electron microscopy， particle size analysis， Zeta potential measurement， infrared spectroscopy， vibrating sample magnetometer and X-ray diffraction. Under the optimal adsorption desorption conditions， the MSPE-MS platform could achieve high selectivity and sensitivity（the detection limit was determined to be as low as 0.1 fmol） for phosphopeptides. Finally， the method was applied to the determination of phosphopeptides in nonfat milk， showing great potential in the detection of low-abundance phosphopeptides in real complex biological samples.