Study of the Fragmentation Patterns of the Phosphate-Arginine Noncovalent Bond
2005; American Chemical Society; Volume: 4; Issue: 6 Linguagem: Inglês
10.1021/pr050261d
ISSN1535-3907
AutoresShelley N. Jackson, Wang, Amina S. Woods,
Tópico(s)Analytical Chemistry and Chromatography
ResumoOur previous work has highlighted the role of certain amino acid residues, mainly two or more adjacent arginine on one peptide and two or more adjacent glutamate, or aspartate, or a phosphorylated residue on the other in the formation of noncovalent complexes (NCX) between peptides. In the present study, we employ ESI−MS to investigate the gas-phase stability and dissociation pathways of the NCX of a basic peptide VLRRRRKRVN, an epitope from the third intracellular loop of the dopamine D2 receptor, with the phosphopetide SVSTDpTpSAE, an epitope from the cannabinoid CB1 carboxyl terminus. ESI−MS/MS analysis of the NCX between VLRRRRKRVN and SVSTDpTpSAE suggests two dissociation pathways for the NCX. The major pathway is the disruption of the electrostatic interactions between the Arg residues and the phosphate groups, while an alternative pathway is also recorded, in which the complex is dissociated along the covalent bond between the oxygen from either Thr or Ser and HPO3. To verify the alternative pathway, we have used an ion trap instrument to conduct MS3 analysis on the product ions of both dissociation pathways. Keywords: phosphate−arginine interaction • receptor heteromerization • gas phase stability • fragmentation pathways • noncovalent complexes
Referência(s)