METHOD TO CORRELATE TANDEM MASS-SPECTRA OF MODIFIED PEPTIDES TO AMINO-ACID-SEQUENCES IN THE PROTEIN DATABASE
METHOD TO CORRELATE TANDEM MASS-SPECTRA OF MODIFIED PEPTIDES TO AMINO-ACID-SEQUENCES IN THE PROTEIN DATABASE
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DOI：
10.1021/ac00104a020
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发表时间：
1995-04-15
影响因子：
7.4
通讯作者：
SCHIELTZ, D
中科院分区：
文献类型：
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作者：
YATES, JR;ENG, JK;SCHIELTZ, D
一种关联低能下产生的修饰肽的未解释串联质谱的方法（10-50 eV）碰撞条件下，与蛋白质数据库中的氨基酸序列进行碰撞。在含有共价修饰的肽的串联质谱中观察到的断裂模式用于直接搜索和拟合数据库中的线性氨基酸序列，与修饰位点相关的特定信息不包含在数据库的基于字符的序列信息中。该搜索方法在一次通过数据库时将每个推定的修饰位点视为修饰的和未修饰的，并且同时考虑多达三个不同的修饰位点，如果串联质谱不代表修饰的肽，则搜索方法将识别正确的序列。用含有修饰的肽（例如S-羧甲基化半胱氨酸、氧化甲硫氨酸、磷酸丝氨酸、磷酸苏氨酸或磷酸酪氨酸）证明了这种方法。此外，使用扫描方法，其中中性丢失扫描用于在单个色谱运行期间启动双电荷磷酸化肽的产物离子MS/MS谱的采集，用于数据库搜索算法的数据分析，本文所述的方法提供了一种方便的方法来匹配修饰肽的新生串联质谱与蛋白质数据库中的序列，从而鉴定以前未知的修改。
A method to correlate uninterpreted tandem mass spectra of modified peptides, produced under low-energy (10-50 eV) collision conditions, with amino acid sequences in a protein database has been developed, The fragmentation patterns observed in the tandem mass-spectra of peptides containing covalent modifications is used to directly search and fit linear amino acid sequences in the database, Specific information relevant to sites of modification is not contained in the character-based sequence information of the databases, The search method considers each putative modification site as both modified and unmodified in one pass through the database and simultaneously considers up to three different sites of modification, The search method will identify the correct sequence if the tandem mass spectrum did not represent a modified peptide. This approach is demonstrated with peptides containing modifications such as S-carboxymethylated cysteine, oxidized methionine, phosphoserine, phosphothreonine, or phosphotyrosine. In addition, a scanning approach is used in which neutral loss scans are used to initiate the acquisition of product ion MS/MS spectra of doubly charged phosphorylated peptides during a single chromatographic ran for data analysis with the database-searching algorithm, The approach described in this paper provides a convenient method to match the nascent tandem mass spectra of modified peptides to sequences in a protein database and thereby identify previously unknown sites of modification.