CROSS-CORRELATION ALGORITHM FOR CALCULATION OF PEPTIDE MOLECULAR WEIGHT FROM TA

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。我们已经开发了一种方法来确定肽离子的分子量直接从其相应的串联质谱使用互相关函数。我们已经证明，从复杂蛋白质混合物的胰蛋白酶消化鉴定的串联质谱中，约90%的单同位素分子量可以计算出来。计算的单同位素质量的精度取决于所分析光谱的分辨率和质量精度，但线性离子阱质谱通常<0.25 amu。对于低分辨率离子阱数据，计算精确的单同位素分子量的能力将显著提高数据库搜索的速度和性能，而典型的质量精度为~ 3amu。此外，该策略还可用于识别在数据无关的碰撞激活解离中使用大离子选择窗口获得的串联质谱的前体离子，并具有识别多路串联质谱的潜力

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. We have developed an approach to identify the molecular weight of a peptide ion directly from its corresponding tandem mass spectrum using a cross-correlation function. We have shown that the monoisotopic molecular weight can be calculated for ~90% of tandem mass spectra identified from tryptic digests of complex protein mixtures. The accuracy of the calculated monoisotopic masses was dependent on the resolution and mass accuracy of the spectra analyzed, but was typically <0.25 amu for linear ion trap mass spectra. The ability to calculate accurate monoisotopic molecular weights for low-resolution ion trap data should significantly improve both the speed and performance of database searches for which typical mass accuracies of ~3 amu are employed. In addition, this strategy can also be used to identify the precursor ion for tandem mass spectra acquired using large ion selection windows in data-independent collision-activated dissociation and has the potential to identify multiplexed tandem mass sp