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Studies on the distribution of oligodeoxynucleotide charge states in the gas phase by ion spray mass spectrometry
Author(s) -
Tong Xinchun,
Henion Jack,
Ganem Bruce
Publication year - 1995
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/jms.1190300612
Subject(s) - chemistry , guanosine , nucleoside , cytidine , mass spectrometry , ion , protonation , nucleic acid , analytical chemistry (journal) , pyrimidine , chromatography , stereochemistry , organic chemistry , biochemistry , enzyme
The naturally occurring purine and pyrimidine heterocycles found in nucleic acids differ significantly in their basicity. To investigate whether such differences may provide useful mass spectrometric information about nucleic acid sequence and/or composition, the distribution of charge states in a series of oligodeoxynucleotide gas‐phase ions was studied by ion spray mass spectrometry (MS). Hexadeoxynucleotides of adenosine, cytidine, guanosine and thymidine were evaluated over the pH range 2.6–7.0 using negative‐ion MS. A significant reduction in the maximum charge state was noted for d(pA) 6 , d(pC) 6 and d(G) 6 at low pH, while the maximum charge state observed for d(pT) 6 was independent of pH. These effects displayed a good correlation with the p K a values of the respective nucleoside bases. The findings suggest that charge‐state reduction probably resulted from internal charge neutrazation by gas‐phase protonation of the nucleoside base.