File Download

There are no files associated with this item.

  Links for fulltext
     (May Require Subscription)
Supplementary

Article: Discovery and Mechanistic Studies of Facile N‑Terminal Cα−C Bond Cleavages in the Dissociation of Tyrosine-Containing Peptide Radical Cations

TitleDiscovery and Mechanistic Studies of Facile N‑Terminal Cα−C Bond Cleavages in the Dissociation of Tyrosine-Containing Peptide Radical Cations
Authors
Issue Date2014
Citation
J. Phys. Chem. B, 2014, v. 118, p. 4273-4281 How to Cite?
AbstractFascinating N-terminal Cα−C bond cleavages in a series of nonbasic tyrosine-containing peptide radical cations have been observed under low-energy collision-induced dissociation (CID), leading to the generation of rarely observed x-type radical fragments, with significant abundances. CID experiments of the radical cations of the alanyltyrosylglycine tripeptide and its analogues suggested that the N-terminal Cα−C bond cleavage, yielding its [x2 + H]•+ radical cation, does not involve an N-terminal α-carbon-centered radical. Theoretical examination of a prototypical radical cation of the alanyltyrosine dipeptide, using density functional theory calculations, suggested that direct N-terminal Cα−C bond cleavage could produce an ion−molecule complex formed between the incipient a1+ and x1• fragments. Subsequent proton transfer from the iminium nitrogen atom in a1+ to the acyl carbon atom in x1• results in the observable [x1 + H]•+. The barriers against this novel Cα−C bond cleavage and the competitive N−Cα bond cleavage, forming the complementary [c1 + 2H]+/[z1 − H]•+ ion pair, are similar (ca. 16 kcal mol−1). Rice−Ramsperger−Kassel−Marcus modeling revealed that [x1 + H]•+ and [c1 + 2H]+ species are formed with comparable rates, in agreement with energy-resolved CID experiments for [AY]•+.
Persistent Identifierhttp://hdl.handle.net/10722/202604
ISI Accession Number ID

 

DC FieldValueLanguage
dc.contributor.authorMU, Xen_US
dc.contributor.authorSong, Ten_US
dc.contributor.authorXU, Men_US
dc.contributor.authorLAI, CKen_US
dc.contributor.authorSiu, CKen_US
dc.contributor.authorLaskin, Jen_US
dc.contributor.authorChu, IKen_US
dc.date.accessioned2014-09-19T08:42:25Z-
dc.date.available2014-09-19T08:42:25Z-
dc.date.issued2014en_US
dc.identifier.citationJ. Phys. Chem. B, 2014, v. 118, p. 4273-4281en_US
dc.identifier.urihttp://hdl.handle.net/10722/202604-
dc.description.abstractFascinating N-terminal Cα−C bond cleavages in a series of nonbasic tyrosine-containing peptide radical cations have been observed under low-energy collision-induced dissociation (CID), leading to the generation of rarely observed x-type radical fragments, with significant abundances. CID experiments of the radical cations of the alanyltyrosylglycine tripeptide and its analogues suggested that the N-terminal Cα−C bond cleavage, yielding its [x2 + H]•+ radical cation, does not involve an N-terminal α-carbon-centered radical. Theoretical examination of a prototypical radical cation of the alanyltyrosine dipeptide, using density functional theory calculations, suggested that direct N-terminal Cα−C bond cleavage could produce an ion−molecule complex formed between the incipient a1+ and x1• fragments. Subsequent proton transfer from the iminium nitrogen atom in a1+ to the acyl carbon atom in x1• results in the observable [x1 + H]•+. The barriers against this novel Cα−C bond cleavage and the competitive N−Cα bond cleavage, forming the complementary [c1 + 2H]+/[z1 − H]•+ ion pair, are similar (ca. 16 kcal mol−1). Rice−Ramsperger−Kassel−Marcus modeling revealed that [x1 + H]•+ and [c1 + 2H]+ species are formed with comparable rates, in agreement with energy-resolved CID experiments for [AY]•+.en_US
dc.languageengen_US
dc.relation.ispartofJ. Phys. Chem. Ben_US
dc.titleDiscovery and Mechanistic Studies of Facile N‑Terminal Cα−C Bond Cleavages in the Dissociation of Tyrosine-Containing Peptide Radical Cationsen_US
dc.typeArticleen_US
dc.identifier.emailSong, T: songtaoo@hku.hken_US
dc.identifier.emailChu, IK: ivankchu@hku.hken_US
dc.identifier.authorityChu, IK=rp00683en_US
dc.identifier.doi10.1021/jp410525fen_US
dc.identifier.pmid24678922-
dc.identifier.hkuros239003en_US
dc.identifier.volume118en_US
dc.identifier.spage4273en_US
dc.identifier.epage4281en_US
dc.identifier.isiWOS:000335113600002-

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats