Can metal ions be used as gas-phase disulfide bond cleavage reagents? A survey of coinage metal complexes of model peptides containing an intermolecular disulfide bond.
The role that a metal ion can have in promoting disulfide bond cleavage has been assessed by surveying the tandem mass spectra of the following metal complexes of model peptides containing an intermolecular disulfide bond: [M--H+Cu(II)](+); [M--H+Cu(II)(bipy)](+); [M+Ag(I)](+); and [M+Au(I)(PMe(3))](+). In comparison to previously studied protonated peptides, these binary and ternary metal complexes generally yield more abundant S--S and/or C--S bond cleavage. In general, [M--H+Cu(II)](+) ions cleave the adjacent C--S bond more readily, while the [M+Au(I)(PMe(3))](+) ion cleaves the S--S bond more readily. The ternary metal complex [M--H+Cu(II)(bipy)](+), on the other hand, fragments by exclusive loss of the bipyridyl ligand for the larger model peptides studied. Of all coinage metal systems studied, Me(3)PAu(+) is superior in promoting disulfide bond cleavage.
Lioe
Hadi
H
School of Chemistry, University of Melbourne, Victoria 3010, Australia.
Duan
Mubing
M
O'Hair
Richard A J
RA
D001665:Binding Sites; D003432:Cross-Linking Reagents / Q000737:chemistry; D004220:Disulfides / Q000737:chemistry*; D005740:Gases / Q000737:chemistry*; D007202:Indicators and Reagents / Q000737:chemistry; D007477:Ions; D008670:Metals / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D044367:Phase Transition; D011485:Protein Binding; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D003432:Cross-Linking Reagents; D004220:Disulfides; D005740:Gases; D007202:Indicators and Reagents; D007477:Ions; D008670:Metals; D010455:Peptides