N-terminal peptide sequence repetition influences the kinetics of backbone fragmentation: a manifestation of the Jahn-Teller effect?
J Am Soc Mass Spectrom
; 24(11): 1671-5, 2013 Nov.
Article
em En
| MEDLINE
| ID: mdl-23633015
ABSTRACT
Analysis of large (>10,000 entries) databases consisting of high-resolution tandem mass spectra of peptide dications revealed with high statistical significance (P < 1[Symbol see text]10(-3)) that peptides with non-identical first two N-terminal amino acids undergo cleavages of the second peptide bond at higher rates than repetitive sequences composed of the same amino acids (i.e., in general AB- and BA- bonds cleave more often than AA- and BB- bonds). This effect seems to depend upon the collisional energy, being stronger at lower energies. The phenomenon is likely to indicate the presence of the diketopiperazine structure for at least some b2 (+) ions. When consisting of two identical amino acids, these species should form through intermediates that have a symmetric geometry and, thus, must be subject to the Jahn-Teller effect that reduces the stability of such systems.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Peptídeos
/
Cátions Bivalentes
/
Sequência de Aminoácidos
Idioma:
En
Revista:
J Am Soc Mass Spectrom
Ano de publicação:
2013
Tipo de documento:
Article