Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, USA.
J Proteome Res. 2010 Oct 1;9(10):5492-5. doi: 10.1021/pr100291q.
The mass defect of a substance can be used in mass spectral analysis to identify peaks as likely belonging to a compound class, such as peptides, if the mass defect is within the known range for that compound class. For peptides, a range of possible mass defects was calculated previously, using a set of theoretical peptides, where all possible amino acid combinations were considered (Mann , M. Abstract from the 43(rd) Annual Conference on Mass Spectrometry and Allied Topics; Conference Proceedings , 1995). We compare that range of theoretical peptide mass defects to new values obtained from in silico tryptic digests of proteins that are abundant in human serum and human seminal fluid. The range of mass defect values encompassing 95% of peptides for the human protein data sets was found to be up to 50% smaller than the previously reported mass defect range for the theoretical peptides. The smaller range established for human tryptic peptides can be used to improve peptide mass defect filters by excluding more species that are not likely to be peptides, thus improving filter selectivity for peptides during proteomic data analysis.
物质的质量缺陷可用于质谱分析，以确定峰是否可能属于化合物类别，如肽，如果质量缺陷在该化合物类别的已知范围内。对于肽，先前使用一组理论肽计算了可能的质量缺陷范围，其中考虑了所有可能的氨基酸组合（Mann，M. 第 43 届年度质谱及其相关主题会议摘要；会议录，1995 年）。我们将该理论肽质量缺陷范围与从富含人血清和人精液的蛋白质的计算机切肽消化中获得的新值进行了比较。在人类蛋白质数据集范围内包含 95%肽的质量缺陷值范围比先前报道的理论肽的质量缺陷范围小 50%。为人类胰蛋白酶肽建立的较小范围可用于通过排除更多不太可能是肽的物种来改进肽质量缺陷过滤器，从而在蛋白质组数据分析期间提高肽的过滤器选择性。
