Zidarov D, Thibault P, Evans M J, Bertrand M J
Department of Chemistry, Université de Montréal, Québec, Canada.
Biomed Environ Mass Spectrom. 1990 Jan;19(1):13-26. doi: 10.1002/bms.1200190103.
The determination of the amino acid composition and sequence of a peptide, using both conventional and tandem fast atom bombardment mass spectrometry, is presented. First a list of potential empirical formulae is generated using the accurate mass and isotopic peak intensity ratios from the molecular ion cluster. The formulae are mathematically analyzed to ensure that they correspond to linear peptides composed of 19 common amino acids. Then using the ions below m/z 160 Da, which are characteristic of the amino acid content of the peptide, the formulae are decomposed into possible amino acid compositions. From each composition sequences are generated and their predicted fragment ions are compared to ions present in the mass spectrum. A score based on the intensities and the occurrence of consecutive sequence fragments is calculated. Finally sequences with the ten highest scores are retained. Analyses performed on typical peptides with molecular weights below 1500 Da indicate that identification can generally be achieved using this approach.
本文介绍了使用常规和串联快原子轰击质谱法测定肽的氨基酸组成和序列的方法。首先，利用分子离子簇的精确质量和同位素峰强度比生成一系列潜在的经验式。对这些式子进行数学分析，以确保它们对应于由19种常见氨基酸组成的线性肽。然后，利用低于m/z 160 Da的离子（这些离子是肽氨基酸含量的特征离子），将这些式子分解为可能的氨基酸组成。从每种组成生成序列，并将其预测的碎片离子与质谱中存在的离子进行比较。计算基于强度和连续序列片段出现情况的得分。最后保留得分最高的十个序列。对分子量低于1500 Da的典型肽进行的分析表明，使用这种方法通常可以实现鉴定。
