Multistep tandem mass spectrometry for sequencing cyclic peptides axinastatin 1 and deducing fragmentation pathways

作者：Qi Wei^*; Jia Chen Xi; He Zhi Min; Qiao Bin

来源：Acta Chimica Sinica, 2007, 65(3): 233-238.

• cyclic peptide
• sequencing
• tandem mass spectrometry
• fragmentation pathway

Marine cyclic peptide Axinastatin 1 was synthesized. In this process the peptide was sequenced by tandem mass spectrometry. Based on the b(x)-y(z) pathway, the linear peptide was sequenced through complementarities of the sequence information supplied by b and y ions in the same MS2 spectrum. The cyclopeptide was sequenced based on the b(x)-> b(x-1) pathway. Two sets of b ions were obtained through sequentially removing one amino acid residue in each stage of MS/MS. According to above information, the cyclopeptide sequence was elucidated and the cyclic structure was concluded. The rearrangement of b ions was also observed. All the mechanisms were discussed and verified by semiempirical PM3 and AMI quantum-chemical calculations. For the rearrangement of b ions, a hypothesis of translation structure was proposed.

• 出版日期2007-2-14
• 单位天津大学