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Gas-phase intermolecular phosphate transfer within a phosphohistidine phosphopeptide dimer.

Gonzalez-Sanchez MB, Lanucara F, Hardman GE, Eyers CE - Int J Mass Spectrom (2014)

Bottom Line: Analysis of the products of low-energy CID demonstrated formation of a doubly 'phosphorylated' product ion arising from intermolecular gas-phase phosphate transfer within a phosphopeptide dimer.The results are explained by the formation of a homodimeric phosphohistidine (pHis) peptide non-covalent complex (NCX), likely stabilized by the electrostatic interaction between the pHis phosphate group and the protonated C-terminal lysine residue of the peptide.To the best of our knowledge this is the first report of intermolecular gas-phase phosphate transfer from one phosphopeptide to another, leading to a doubly phosphorylated peptide product ion.

View Article: PubMed Central - PubMed

Affiliation: Michael Barber Centre for Mass Spectrometry, School of Chemistry, Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK.

ABSTRACT

The hydrogen bonds and electrostatic interactions that form between the protonated side chain of a basic residue and the negatively charged phosphate of a phosphopeptide can play crucial roles in governing their dissociation pathways under low-energy collision-induced dissociation (CID). Understanding how phosphoramidate (i.e. phosphohistidine, phospholysine and phosphoarginine), rather than phosphomonoester-containing peptides behave during CID is paramount in investigation of these problematic species by tandem mass spectrometry. To this end, a synthetic peptide containing either phosphohistidine (pHis) or phospholysine (pLys) was analyzed by ESI-MS using a Paul-type ion trap (AmaZon, Bruker) and by traveling wave ion mobility-mass spectrometry (Synapt G2-Si, Waters). Analysis of the products of low-energy CID demonstrated formation of a doubly 'phosphorylated' product ion arising from intermolecular gas-phase phosphate transfer within a phosphopeptide dimer. The results are explained by the formation of a homodimeric phosphohistidine (pHis) peptide non-covalent complex (NCX), likely stabilized by the electrostatic interaction between the pHis phosphate group and the protonated C-terminal lysine residue of the peptide. To the best of our knowledge this is the first report of intermolecular gas-phase phosphate transfer from one phosphopeptide to another, leading to a doubly phosphorylated peptide product ion.

No MeSH data available.


Related in: MedlinePlus

Proposed mechanism for the formation of the ions at m/z 1459.8. The scheme depicts a homodimer of the phosphopeptide FVIAFILpHLVK (m/z 1379.8), whose components can undergo elimination of metaphosphoric acid HPO3 and generation of a transient ternary complex, which then evolves to give the dephosphorylated peptide at m/z 1299.8 and the ‘doubly’ phosphorylated peptide at m/z 1459.8.
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fig0030: Proposed mechanism for the formation of the ions at m/z 1459.8. The scheme depicts a homodimer of the phosphopeptide FVIAFILpHLVK (m/z 1379.8), whose components can undergo elimination of metaphosphoric acid HPO3 and generation of a transient ternary complex, which then evolves to give the dephosphorylated peptide at m/z 1299.8 and the ‘doubly’ phosphorylated peptide at m/z 1459.8.

Mentions: Based on current understanding, it is likely that the additional phosphate group is kept within the complex by means of hydrogen bonds and charge–dipole interactions with the C-terminal protonated Lys residue (Scheme 1). The peptide under investigation contains a basic C-terminal Lys and can therefore generate a protonated primary amine. Given the well-characterized interaction between a phosphate group and a protonated Lys [22], we anticipated that a similar non-covalent bond could be established between the phosphate on pHis and the ɛ-ammonium group of the C-terminal Lys, thus mimicking the systems previously described [16–19]. If true, this should facilitate the formation of a homodimer via electrostatic and hydrogen bond interactions. Additionally, the Π-electron density of the aromatic imidazole ring of the His and the phenyl ring of the Phe residues could be engaged in a Π-cation interaction with the protonated side chain of the lysine residue, thus contributing to the overall stability of the dimer.


Gas-phase intermolecular phosphate transfer within a phosphohistidine phosphopeptide dimer.

Gonzalez-Sanchez MB, Lanucara F, Hardman GE, Eyers CE - Int J Mass Spectrom (2014)

Proposed mechanism for the formation of the ions at m/z 1459.8. The scheme depicts a homodimer of the phosphopeptide FVIAFILpHLVK (m/z 1379.8), whose components can undergo elimination of metaphosphoric acid HPO3 and generation of a transient ternary complex, which then evolves to give the dephosphorylated peptide at m/z 1299.8 and the ‘doubly’ phosphorylated peptide at m/z 1459.8.
© Copyright Policy - CC BY
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4375673&req=5

fig0030: Proposed mechanism for the formation of the ions at m/z 1459.8. The scheme depicts a homodimer of the phosphopeptide FVIAFILpHLVK (m/z 1379.8), whose components can undergo elimination of metaphosphoric acid HPO3 and generation of a transient ternary complex, which then evolves to give the dephosphorylated peptide at m/z 1299.8 and the ‘doubly’ phosphorylated peptide at m/z 1459.8.
Mentions: Based on current understanding, it is likely that the additional phosphate group is kept within the complex by means of hydrogen bonds and charge–dipole interactions with the C-terminal protonated Lys residue (Scheme 1). The peptide under investigation contains a basic C-terminal Lys and can therefore generate a protonated primary amine. Given the well-characterized interaction between a phosphate group and a protonated Lys [22], we anticipated that a similar non-covalent bond could be established between the phosphate on pHis and the ɛ-ammonium group of the C-terminal Lys, thus mimicking the systems previously described [16–19]. If true, this should facilitate the formation of a homodimer via electrostatic and hydrogen bond interactions. Additionally, the Π-electron density of the aromatic imidazole ring of the His and the phenyl ring of the Phe residues could be engaged in a Π-cation interaction with the protonated side chain of the lysine residue, thus contributing to the overall stability of the dimer.

Bottom Line: Analysis of the products of low-energy CID demonstrated formation of a doubly 'phosphorylated' product ion arising from intermolecular gas-phase phosphate transfer within a phosphopeptide dimer.The results are explained by the formation of a homodimeric phosphohistidine (pHis) peptide non-covalent complex (NCX), likely stabilized by the electrostatic interaction between the pHis phosphate group and the protonated C-terminal lysine residue of the peptide.To the best of our knowledge this is the first report of intermolecular gas-phase phosphate transfer from one phosphopeptide to another, leading to a doubly phosphorylated peptide product ion.

View Article: PubMed Central - PubMed

Affiliation: Michael Barber Centre for Mass Spectrometry, School of Chemistry, Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK.

ABSTRACT

The hydrogen bonds and electrostatic interactions that form between the protonated side chain of a basic residue and the negatively charged phosphate of a phosphopeptide can play crucial roles in governing their dissociation pathways under low-energy collision-induced dissociation (CID). Understanding how phosphoramidate (i.e. phosphohistidine, phospholysine and phosphoarginine), rather than phosphomonoester-containing peptides behave during CID is paramount in investigation of these problematic species by tandem mass spectrometry. To this end, a synthetic peptide containing either phosphohistidine (pHis) or phospholysine (pLys) was analyzed by ESI-MS using a Paul-type ion trap (AmaZon, Bruker) and by traveling wave ion mobility-mass spectrometry (Synapt G2-Si, Waters). Analysis of the products of low-energy CID demonstrated formation of a doubly 'phosphorylated' product ion arising from intermolecular gas-phase phosphate transfer within a phosphopeptide dimer. The results are explained by the formation of a homodimeric phosphohistidine (pHis) peptide non-covalent complex (NCX), likely stabilized by the electrostatic interaction between the pHis phosphate group and the protonated C-terminal lysine residue of the peptide. To the best of our knowledge this is the first report of intermolecular gas-phase phosphate transfer from one phosphopeptide to another, leading to a doubly phosphorylated peptide product ion.

No MeSH data available.


Related in: MedlinePlus