首页 | 本学科首页   官方微博 | 高级检索  
     检索      

Dissociation of multiply charged negative ions for hirudin (54–65), fibrinopeptide B, and insulin A (oxidized)
作者姓名:Ewing NP  Cassady CJ
摘    要:

收稿时间:30 May 2000

Dissociation of multiply charged negative ions for hirudin (54–65), fibrinopeptide B,and insulin A (oxidized)
Ewing NP,Cassady CJ.Dissociation of multiply charged negative ions for hirudin (54–65), fibrinopeptide B,and insulin A (oxidized)[J].Journal of The American Society for Mass Spectrometry,2001,12(1):105-116.
Authors:Nigel P Ewing  Carolyn J Cassady
Institution:Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio, USA.
Abstract:Collision-induced dissociation (CID) was performed on multiply deprotonated ions from three commercial peptides: hirudin (54-65), fibrinopeptide B, and oxidized insulin chain A. Ions were produced by electrospray ionization in a Fourier transform ion cyclotron resonance mass spectrometer. Each of these peptides contains multiple acidic residues, which makes them very difficult to ionize in the positive mode. However, the peptides deprotonate readily making negative ion studies a viable alternative. The CID spectra indicated that the likely deprotonation sites are acidic residues (aspartic, glutamic, and cysteic acids) and the C-terminus. The spectra are rife with c, y, and internal ions, although some a, b, x, and z ions form. Many of the fragment ions were formed from cleavage adjacent to acidic residues, both N- and C-terminal to the acidic site. In addition, neutral loss (e.g., NH3, CH3, H2O, and CO2) was prevalent from both the parent ions and from fragment ions. These neutral eliminations were often indicative of specific amino acid residues. The fragmentation patterns from several charge states of the parent ions, when combined, provide significant primary sequence information. These results suggest that negative mode CID of multiply deprotonated ions provides useful structural information and can be worthwhile for highly acidic peptides that do not form positive ions in abundance.
Keywords:
本文献已被 ScienceDirect PubMed SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号