ISSN:
0306-042X
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Chemical ionization mass spectrometry has been shown to be a useful method for the differentiation of α- and γ-glutamyl dipeptides where the C-terminal amino acids are simple α-amino or α-imino acids without additional functional groups. The α-glutamyl dipeptides lost one and two molecules of H2O from the protonated molecular ion to give fragment ions at [MH—H2O]+ and [MH—2H2O]+. With the γ-glutamyl dipeptides, the characteristic fragment ions of highest intensities were the protonated pyroglutamic acid (pyrrolidone-5-carboxylic acid) ion at m/z 130, and a fragment ion corresponding to the protonated C-terminal amino acid. The procedure does not require derivatization of the dipeptide, and because only small sample sizes are needed it could prove useful for the characterization of synthetic samples and glutamyl dipeptides isolated and purified from biological sources.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bms.1200090606
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