Electrospray Collision-induced Dissociation Mass Spectra of Positively Charged Oligonucleotides

✍ Scribed by PingPing Wang; Michael G. Bartlett; LeRoy B. Martin

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 238 KB
• Volume: 11
• Category: Article
• ISSN: 0951-4198
• DOI: 10.1002/(sici)1097-0231(199705)11:8<846::aid-rcm928>3.0.co;2-9

✦ Synopsis

Positive ion collision-induced dissociation (CID) mass spectra of oligonucleotides provide qualitatively similar fragmentation patterns to CID mass spectra generated from negative ion precursors. The major sequence ion series w and a-base are still abundant enough to be useful for the determination of the sequence of an oligonucleotide. The application of sequencing to both positively and negatively charged precursor ions up to the 20-mer level are shown. The positive ion electrospray charge-state distributions are found to be sensitive to the base composition of the oligonucleotide. In the case of homopolymers containing the bases adenine, guanine and cytodine the average charge state is found to be similar. However, the average charge state of a homopolymer containing the base thymine is significantly lower. In addition, the CID mass spectra of this oligonucleotide results in the formation of x-2H and z-2H type ions exclusively. These differences are thought to be caused due to the phosphate backbone being the site of protonation rather than the base.