Sequence determination of peptides using mass spectrometry plays a crucial role in the bottom-up approaches for the identification of proteins. It is crucially important to minimise false detection and validate sequence of the peptides in order to correctly identify a protein. Chemical modification of peptides followed by mass spectrometry is an option for improving the spectral quality. In silico-derived tryptic peptides with different N-terminal amino acids were designed from human proteins and synthesized. The effect of acetylation on the fragmentation of peptides was studied. N-terminal acetylation of the tryptic peptides was shown to form b1-ions, improve the abundance and occurrence of b-ions. In some cases, the intensity and occurrence of some y-ions also varied. Thus, it is demonstrated that acetylation plays an important role in improving the de novo sequencing efficiency of the peptides. The acetylation method was extended to tryptic peptides generated from the proteome of an Antarctic bacterium Pseudomonas syringae Lz4W using the proteomics work flow and mass spectra of the peptides were analysed. Comparison of the MS/MS spectra of the acetylated and unacetylated peptides revealed that acetylation helped in improving the spectral quality and validated the peptide sequences. Using this method, 673 proteins of the 1070 proteins identified were validated.

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乙酰化肽的质谱分析：对蛋白质组学的影响

使用质谱法对肽进行序列测定在蛋白质鉴定的自下而上方法中起着至关重要的作用。为了正确识别蛋白质，最大限度地减少错误检测和验证肽序列至关重要。肽的化学修饰，然后进行质谱分析是提高光谱质量的一种选择。从人类蛋白质中设计并合成具有不同 N 端氨基酸的计算机衍生胰蛋白酶肽。研究了乙酰化对肽片段化的影响。显示胰蛋白酶肽的 N 端乙酰化形成 b1 离子，提高 b 离子的丰度和发生率。在某些情况下，一些 y 离子的强度和出现也不同。因此，结果表明，乙酰化在提高肽的从头测序效率方面起着重要作用。使用蛋白质组学工作流程将乙酰化方法扩展到从南极细菌丁香假单胞菌 Lz4W 的蛋白质组产生的胰蛋白酶肽，并分析了肽的质谱。乙酰化和未乙酰化肽的 MS/MS 谱的比较显示乙酰化有助于提高谱质量并验证肽序列。使用这种方法，对鉴定的 1070 种蛋白质中的 673 种蛋白质进行了验证。使用蛋白质组学工作流程将乙酰化方法扩展到从南极细菌丁香假单胞菌 Lz4W 的蛋白质组产生的胰蛋白酶肽，并对肽的质谱进行分析。乙酰化和未乙酰化肽的 MS/MS 谱的比较显示乙酰化有助于提高谱质量并验证肽序列。使用这种方法，对鉴定的 1070 种蛋白质中的 673 种蛋白质进行了验证。使用蛋白质组学工作流程将乙酰化方法扩展到从南极细菌丁香假单胞菌 Lz4W 的蛋白质组产生的胰蛋白酶肽，并分析了肽的质谱。乙酰化和未乙酰化肽的 MS/MS 谱的比较显示乙酰化有助于提高谱质量并验证肽序列。使用这种方法，对鉴定的 1070 种蛋白质中的 673 种蛋白质进行了验证。