Linear energy correlation in the low-energy tandem mass spectra of protonated tripeptides Xxx–Gly–Gly but failure for Gly–Xxx–Gly

✍ Scribed by Daniel G. Morgan; Maurice M. Bursey

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 528 KB
• Volume: 30
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/jms.1190300210

✦ Synopsis

Abstract

The backbone cleavages of protonated tripeptide ions of the series Xxx–Gly–Gly, where Xxx–Gly, Ala, Val, Leu, Ile, Phe, Tyr, Met, Pro and Trp, were studied in a hybrid tandem mass spectrometer. C‐Terminal y‐type ions and N‐terminal a‐ and b‐type ions were noted. A linear relationship between log (intensity of y~2~ divided by the sum of all other product ion intensities) and the proton affinity of the N‐terminal amino acid substituent was found for the series Xxx–Gly–Gly: as the proton affinity of the N‐terminal residue increases, the fraction of y~2~ ion formation decreases. The series of protonated tripeptides Gly–Xxx–Gly, where Xxx = Gly, Ala, Leu, Phe, Tyr, Met and Trp, were also studied.