Amazing stability of phosphate-quaternary amine interactions

Amina S. Woods, Susan C. Moyer, Shelley N. Jackson

Research output: Contribution to journalArticlepeer-review

31 Scopus citations


We have previously used MALDI mass spectrometry to highlight ammonium- or guanidinium-aromatic interactions via cation-φ bonding and ammonium- or guanidinium-phosphate interactions through salt bridge formation. In the present work, the gas-phase stability and dissociation pathways of the interaction between phosphorylated peptides and compounds containing quaternary amines are demonstrated using electrospray ionization mass spectrometry. The presence of one quaternary amine in a compound is enough to form a noncovalent complex with a phosphorylated residue. However, if two quaternary amines are present in one molecule, the electrostatic interactions of the quaternary amines with the phosphate results in a "covalent-like" stability, and these bonds can withstand fragmentation by collision-induced dissociation at energies similar to those that fragment covalent bonds. Such interactions are important in accounting for physiological, pathophysiological, and pharmacological effects of many therapeutic compounds and small molecules containing quaternary amines or phosphates.

Original languageEnglish (US)
Pages (from-to)3423-3427
Number of pages5
JournalJournal of Proteome Research
Issue number8
StatePublished - Aug 2008
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry
  • Chemistry(all)


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