Department of Chemistry, The University of Texas at Austin, 105 East 24th Street, Stop A5300, Austin, Texas 78712, USA.
Anal Chem. 2013 Sep 3;85(17):8313-8. doi: 10.1021/ac401634b. Epub 2013 Aug 15.
The routine analysis of large biomolecules (greater than 30 kDa) has been a challenge for Orbitrap mass spectrometers due to the relatively high kinetic energy of ions entering and within the Orbitrap mass analyzer. This characteristic results in rapid signal decay for large biomolecules due to energetic collisions with background gas molecules. Here, we report a method to significantly enhance the analysis of large biomolecules in an Orbitrap mass spectrometer. The combination of reduced C-trap and higher energy collisional dissociation (HCD) cell bath gas pressures, using helium as the bath gas and trapping ions in the HCD cell prior to mass analysis, greatly increased sensitivity and reduced signal decay for large protein ions. As a result, isotopic resolution of monoclonal immunoglobulin G was achieved, and we have established a new high-mass record for which accurate mass measurement and isotopic resolution have been achieved.
由于进入和在 Orbitrap 质量分析器内的离子具有较高的动能，因此分析大于 30 kDa 的大分子一直是 Orbitrap 质谱仪面临的挑战。这一特性导致大分子由于与背景气体分子的能量碰撞而迅速信号衰减。在此，我们报告了一种可显著增强 Orbitrap 质谱仪中大分子分析的方法。通过降低 C 阱和提高高能碰撞解离（HCD）池的浴气压，使用氦气作为浴气，并在进行质量分析之前将离子困在 HCD 池中，大大提高了大蛋白离子的灵敏度并减少了信号衰减。结果，实现了单克隆免疫球蛋白 G 的同位素分辨率，并且我们建立了一个新的高质量记录，实现了精确质量测量和同位素分辨率。
