On the benefits of acquiring peptide fragment ions at high measured mass accuracy
On the benefits of acquiring peptide fragment ions at high measured mass accuracy
复制标题
DOI：
10.1016/j.jasms.2008.02.005
复制
发表时间：
2008-06-01
影响因子：
3.2
通讯作者：
Goodlett, David R.
中科院分区：
文献类型：
--
作者：
Scherl, Alexander;Shaffer, Scott A.;Goodlett, David R.
介绍了在线性离子阱傅里叶变换混合仪器中通过肽的碰撞诱导解离（CID）获得串联质谱的优点和缺点。这些仪器提供了将碎片离子从线性离子阱转移到基于FT的分析仪的可能性，以进行高分辨率和高质量精度的分析。此外，在离子从线性离子阱（LTQ）转移到FT分析器期间执行CID也可以在包含附加碰撞室（即，LTQ-轨道阱中的“C阱”），导致在整个m/Z范围内的串联质谱，并且不受LTQ的喷射q值的限制。我们的研究结果表明，这些扫描模式具有较低的占空比，比串联质谱中获得的LTQ与标称质量分辨率，通常会导致在复杂样品的数据依赖性分析过程中较少的肽识别。然而，更高的测量质量准确度和分辨率提供了更高的特异性，因此在肽串联质谱的数据库搜索期间，对于相同数量的真阳性，提供了更低的假阳性率。此外，这种数据采集模式极大地促进了对修饰的和意想不到的肽的搜索。因此，可以得出结论，收购串联质谱数据与高测量质量的准确性和分辨率是一个有竞争力的替代“经典”的数据采集策略，特别是在复杂的搜索大型数据库的情况下，搜索修饰肽，或肽产生的非特异性裂解。
The advantages and disadvantages of acquiring tandem mass spectra by collision-induced dissociation (CID) of peptides in linear ion trap Fourier-transform hybrid instruments are described. These instruments offer the possibility to transfer fragment ions from the linear ion trap to the FT-based analyzer for analysis with both high resolution and high mass accuracy. In addition, performing CID during the transfer of ions from the linear ion trap (LTQ) to the FT analyzer is also possible in instruments containing an additional collision cell (i.e., the "C-trap" in the LTQ-Orbitrap), resulting in tandem mass spectra over the full m/Z range and not limited by the ejection q value of the LTQ. Our results show that these scan modes have lower duty cycles than tandem mass spectra acquired in the LTQ with nominal mass resolution, and typically result in fewer peptide identifications during data-dependent analysis of complex samples. However, the higher measured mass accuracy and resolution provides more specificity and hence provides a lower false positive ratio for the same number of true positives during database search of peptide tandem mass spectra. In addition, the search for modified and unexpected peptides is greatly facilitated with this data acquisition mode. It is therefore concluded that acquisition of tandem mass spectral data with high measured mass accuracy and resolution is a competitive alternative to "classical" data acquisition strategies, especially in situations of complex searches from large databases, searches for modified peptides, or for peptides resulting from unspecific cleavages.