For disulfide-containing peptides, mass spectrometric analyses are rarely comparably studied between their dithiol and disulfide forms. Persulfide ions afforded from peptides with a disulfide ring are from either an unusual N–C^α bond cleavage or a canonical peptide bond cleavage; their isomeric structures are, however, not identified just from peaks of mass spectra.

中文翻译：

---

含二硫键肽 TTCPYCKK 及其类似物 N-Cα 键断裂的质谱和理论研究

对于含二硫键的肽，质谱分析很少在其二硫醇和二硫键形式之间进行比较研究。由具有二硫环的肽提供的过硫离子来自不寻常的 N-C ^α键断裂或典型的肽键断裂；然而，它们的异构结构并不能仅从质谱峰中识别出来。