PERFORMANCE OF A LINEAR ION TRAP-ORBITRAP HYBRID FOR PEPTIDE ANALYSIS

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。蛋白质组学分析消化的复杂蛋白质混合物已成为识别参与生物过程的蛋白质的有用策略。我们已经评估了一种新型质谱仪的使用，该质谱仪结合了线性离子阱和轨道阱来创建混合串联质谱仪。消化的下颌/舌下唾液样本用于分析。我们发现该仪器的质量分辨率超过40000，质量测量精度小于2 ppm，用于分析复杂的肽混合物。如此高的质量精度允许消除几乎任何假阳性肽鉴定，这表明肽不匹配用于消化样品的蛋白酶的特异性不应自动被认为是假阳性。线性离子阱的串联质谱和轨道阱的串联质谱具有非常相似的离子丰度比。我们得出结论，该仪器将非常适合于散弹枪蛋白质组学类型的分析。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Proteomic analysis of digested complex protein mixtures has become a useful strategy to identify proteins involved in biological processes. We have evaluated the use of a new mass spectrometer that combines a linear ion trap and an Orbitrap to create a hybrid tandem mass spectrometer. A digested submandibular/sublingual saliva sample was used for the analysis. We find the instrument is capable of mass resolution in excess of 40 000 and mass measurement accuracies of less than 2 ppm for the analysis of complex peptide mixtures. Such high mass accuracy allowed the elimination of virtually any false positive peptide identifications, suggesting that peptides that do not match the specificity of the protease used in the digestion of the sample should not automatically be considered as false positives. Tandem mass spectra from the linear ion trap and from the Orbitrap have very similar ion abundance ratios. We conclude this instrument will be well suited for shotgun proteomic types of analyses.