Improving de Novo Sequencing of Peptides Using a Charged Tag and C-Terminal Digestion
作者:Weibin Chen、Peter J. Lee、Henry Shion、Nicholas Ellor、John C. Gebler
DOI:10.1021/ac061670b
日期:2007.2.1
An improved method for peptide de novo sequencing by MALDI mass spectrometry is presented. The method couples a charge derivatization reaction with C-terminal digestion to modify tryptic peptides. The charge derivatization attaches a fixed charge group onto the N-termini of peptides, and the enzymatic digestion after the derivatization step removes C-terminal basic amino acid residues such as arginine and lysine. The fragmentation of the modified peptide(s) under low-energy CID conditions (MALDI Q-TOF mass spectrometer) yields a simplified yet complete ion series of the peptide sequence. The validity of the method is demonstrated by the results from several model protein digests, where peptide sequences were correctly deduced either manually or through an automated sequencing program.
本文介绍了一种通过 MALDI 质谱进行肽从头测序的改进方法。该方法将电荷衍生反应与 C 端消化结合起来,对胰蛋白酶肽进行修饰。电荷衍生将一个固定的电荷基团附着在肽的 N 端,衍生步骤后的酶解去除 C 端基本氨基酸残基,如精氨酸和赖氨酸。在低能 CID 条件下(MALDI Q-TOF 质谱仪)对修饰肽进行碎裂,可得到简化但完整的肽序列离子系列。几种蛋白质消化模型的结果证明了该方法的有效性,无论是手动还是通过自动测序程序,都能正确推断出肽序列。