ISSN:
1052-9306
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The extent of C-methylation, an artifact of the permethylation procedure used to derivatize peptides for mass spectrometric sequencing, was investigated by mass spectrometry. Ten glycine-containing peptides were N-acetylated and then permethylated by the Hakomori method and analyzed by chemical ionization and, in some cases, by electron ionization mass spectrometry. A comparative study was made of the tripeptides Gly Pro Ala and Ala Pro Gly, derivatized by three permethylation procedures. The results show that while C-methylation occurs primarily at glycine, other amino acids (Gln, Glu, Met, Tyr) are also C-methylated, but to a lesser degree. The extent to which C-methylation occurs varies widely and depends on residue position and on the identity of neighboring residues. Such artifacts could lead to serious errors in peptide sequences determined by mass spectrometry, especially when mixtures of peptides are analyzed.
Additional Material:
4 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bms.1200020503
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