Abstract The fragmentation statistics were analyzed to study the fragmentation characteristics of quadrupole ion trap CID (Collision-Induced Dissociation) spectra extracted from the human peptide library in the NIST library. Instead of using intensity information, usually considered earlier, here the frequency of occurrence of the fragment ion peaks and its neutral loss events were analyzed with respect to the cleavage position along the peptide backbone and residue at the cleavage site. The analysis demonstrated the significance of the residues and the position of the cleavage site associated with neutral loss events. The analysis shows that the frequency of occurrence of neutral loss peaks has nearly similar proportion along the length of the peptide, but it increases towards the middle of the peptide. Cleavage sites H–H/R/K triggers the generation of the fragment, bn+18 peaks. Neutral loss fragment, y-17 is observed at higher frequencies than its corresponding y-ion peaks, when arginine is on the C- terminal side of the cleavage site. In the case of consecutive loss of neutral fragments, acidic amino acids-aspartic acid and glutamic acid cause decrease in the b-45 & y-45 peaks and increase in b-44, y-44 and b-46, y-46 peaks, while its amide-asparagine and glutamine show the inverse behavior for both b-type and y-type ion.

中文翻译：

---

碰撞诱导解离谱中肽碎裂模式中中性丢失峰的表征

摘要 分析碎裂统计以研究从NIST 库中人肽库中提取的四极杆离子阱CID（碰撞诱导解离）光谱的碎裂特征。此处不使用通常较早考虑的强度信息，而是根据沿肽主链的裂解位置和裂解位点的残基分析碎片离子峰的出现频率及其中性丢失事件。分析证明了残基的重要性和与中性丢失事件相关的切割位点的位置。分析表明，中性丢失峰的出现频率沿肽段长度具有几乎相似的比例，但在肽段中部增加。裂解位点 H–H/R/K 触发片段 bn+18 峰的生成。当精氨酸位于切割位点的 C 端侧时，中性丢失片段 y-17 的频率高于其相应的 y 离子峰。在中性片段连续丢失的情况下，酸性氨基酸-天冬氨酸和谷氨酸导致b-45和y-45峰减少，b-44、y-44和b-46、y-46峰增加，而其酰胺-天冬酰胺和谷氨酰胺对 b 型和 y 型离子显示出相反的行为。