Department of Molecular Medicine and Surgery, Section of Neurogenetics, Karolinska Institutet, SE-171 76 Stockholm, Sweden.
Anal Chem. 2010 Mar 1;82(5):1964-74. doi: 10.1021/ac902712f.
The imaging capability and high detection sensitivity of time-of-flight secondary ion mass spectrometry (ToF-SIMS) makes it a potentially attractive complement to other mass spectrometry methods, such as ESI and MALDI, for the analysis of proteins and peptides. We have explored this possibility by performing a systematic analysis of synthetic opioid and amyloid peptides with ToF-SIMS using Bi(3)(+) and Au(3)(+) primary ions. In the low mass region of the spectra, a number of single amino acid ion peaks were detected, providing information about the amino acid content in each peptide. In the medium and high mass range of the spectra, peaks corresponding to multiple amino acid ions (backbone cleavage ions) as well as molecular ions were detected, allowing for the determination of the amino acid sequence and the molecular mass of the entire peptide, respectively. Detection efficiencies were determined for the molecular ions of some of the peptides, indicating detection limits in the attomole range. The fragmentation patterns observed in the ToF-SIMS analysis of opioid and amyloid peptides showed interesting similarities with collision-induced dissociation (CID) studies using other mass spectrometry methods. The present work provides important progress toward ToF-SIMS proteomics.
飞行时间二次离子质谱（ToF-SIMS）的成像能力和高检测灵敏度使其成为其他质谱方法（如 ESI 和 MALDI）的潜在有吸引力的补充，可用于分析蛋白质和肽。我们通过使用 Bi(3)(+)和 Au(3)(+)初级离子对合成阿片类和淀粉样肽进行系统的 ToF-SIMS 分析，探索了这种可能性。在谱的低质量区域，检测到许多单个氨基酸离子峰，提供了每个肽中氨基酸含量的信息。在谱的中高质量范围，检测到对应于多个氨基酸离子（骨干裂解离子）以及分子离子的峰，分别允许确定整个肽的氨基酸序列和分子量。对一些肽的分子离子的检测效率进行了测定，表明检测限在飞摩尔范围内。在使用其他质谱方法进行的阿片肽和淀粉样肽的 CID 研究中观察到的碎裂模式与 ToF-SIMS 分析显示出有趣的相似性。本工作朝着 ToF-SIMS 蛋白质组学迈出了重要的一步。
