Formation of b2+ ions from protonated peptides: An ab initio study

Béla Paizs, G. Lendvay, K. Vékey, Sándor Suhai

Research output: Contribution to journalArticle

124 Citations (Scopus)

Abstract

Systematic ab initio calculations were performed to reveal the mechanism of formation of stable b2+ ions formed during fragmentation of protonated peptides and proteins. Stable oxazolone-type cyclic b2+ ions are formed from parent ions containing the -C(O)-N-C-C(O)-unit in a two-step process. In the first step the C-N bond of an N-protonated peptide breaks and, simultaneously, ring closure takes place in the remaining -C(O)-N-C-C(O)- fragment leading to the formation of a charged oxazolone-type ring. This reaction takes place through an approximately 10 kcal mol-1 high barrier. The product of this step is a charge-transfer type ion-molecule complex which decomposes in the next step to form the b2+ ion by dropping the amine analogue (C-terminal amino acid or peptide fragment). The dissociation energy of the complex is larger than the height of the barrier through which it was formed so that when the complex decomposes there is not much excess energy to be released as kinetic energy. The alternative multistep mechanism, involving formation of an open-chain acylium ion in the first step and ring closure in the second, is energetically highly unfavorable.

Original languageEnglish
Pages (from-to)525-533
Number of pages9
JournalRapid Communications in Mass Spectrometry
Volume13
Issue number6
DOIs
Publication statusPublished - 1999

Fingerprint

Ions
Peptides
Oxazolone
Peptide Fragments
Kinetic energy
Amines
Charge transfer
Amino Acids
Molecules
Proteins

ASJC Scopus subject areas

  • Analytical Chemistry
  • Spectroscopy

Cite this

Formation of b2+ ions from protonated peptides : An ab initio study. / Paizs, Béla; Lendvay, G.; Vékey, K.; Suhai, Sándor.

In: Rapid Communications in Mass Spectrometry, Vol. 13, No. 6, 1999, p. 525-533.

Research output: Contribution to journalArticle

@article{c6ec8b5c212045f8849d8c6e2db8c138,
title = "Formation of b2+ ions from protonated peptides: An ab initio study",
abstract = "Systematic ab initio calculations were performed to reveal the mechanism of formation of stable b2+ ions formed during fragmentation of protonated peptides and proteins. Stable oxazolone-type cyclic b2+ ions are formed from parent ions containing the -C(O)-N-C-C(O)-unit in a two-step process. In the first step the C-N bond of an N-protonated peptide breaks and, simultaneously, ring closure takes place in the remaining -C(O)-N-C-C(O)- fragment leading to the formation of a charged oxazolone-type ring. This reaction takes place through an approximately 10 kcal mol-1 high barrier. The product of this step is a charge-transfer type ion-molecule complex which decomposes in the next step to form the b2+ ion by dropping the amine analogue (C-terminal amino acid or peptide fragment). The dissociation energy of the complex is larger than the height of the barrier through which it was formed so that when the complex decomposes there is not much excess energy to be released as kinetic energy. The alternative multistep mechanism, involving formation of an open-chain acylium ion in the first step and ring closure in the second, is energetically highly unfavorable.",
author = "B{\'e}la Paizs and G. Lendvay and K. V{\'e}key and S{\'a}ndor Suhai",
year = "1999",
doi = "10.1002/(SICI)1097-0231(19990330)13:6<525::AID-RCM519>3.0.CO;2-O",
language = "English",
volume = "13",
pages = "525--533",
journal = "Rapid Communications in Mass Spectrometry",
issn = "0951-4198",
publisher = "John Wiley and Sons Ltd",
number = "6",

}

TY - JOUR

T1 - Formation of b2+ ions from protonated peptides

T2 - An ab initio study

AU - Paizs, Béla

AU - Lendvay, G.

AU - Vékey, K.

AU - Suhai, Sándor

PY - 1999

Y1 - 1999

N2 - Systematic ab initio calculations were performed to reveal the mechanism of formation of stable b2+ ions formed during fragmentation of protonated peptides and proteins. Stable oxazolone-type cyclic b2+ ions are formed from parent ions containing the -C(O)-N-C-C(O)-unit in a two-step process. In the first step the C-N bond of an N-protonated peptide breaks and, simultaneously, ring closure takes place in the remaining -C(O)-N-C-C(O)- fragment leading to the formation of a charged oxazolone-type ring. This reaction takes place through an approximately 10 kcal mol-1 high barrier. The product of this step is a charge-transfer type ion-molecule complex which decomposes in the next step to form the b2+ ion by dropping the amine analogue (C-terminal amino acid or peptide fragment). The dissociation energy of the complex is larger than the height of the barrier through which it was formed so that when the complex decomposes there is not much excess energy to be released as kinetic energy. The alternative multistep mechanism, involving formation of an open-chain acylium ion in the first step and ring closure in the second, is energetically highly unfavorable.

AB - Systematic ab initio calculations were performed to reveal the mechanism of formation of stable b2+ ions formed during fragmentation of protonated peptides and proteins. Stable oxazolone-type cyclic b2+ ions are formed from parent ions containing the -C(O)-N-C-C(O)-unit in a two-step process. In the first step the C-N bond of an N-protonated peptide breaks and, simultaneously, ring closure takes place in the remaining -C(O)-N-C-C(O)- fragment leading to the formation of a charged oxazolone-type ring. This reaction takes place through an approximately 10 kcal mol-1 high barrier. The product of this step is a charge-transfer type ion-molecule complex which decomposes in the next step to form the b2+ ion by dropping the amine analogue (C-terminal amino acid or peptide fragment). The dissociation energy of the complex is larger than the height of the barrier through which it was formed so that when the complex decomposes there is not much excess energy to be released as kinetic energy. The alternative multistep mechanism, involving formation of an open-chain acylium ion in the first step and ring closure in the second, is energetically highly unfavorable.

UR - http://www.scopus.com/inward/record.url?scp=0033060734&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0033060734&partnerID=8YFLogxK

U2 - 10.1002/(SICI)1097-0231(19990330)13:6<525::AID-RCM519>3.0.CO;2-O

DO - 10.1002/(SICI)1097-0231(19990330)13:6<525::AID-RCM519>3.0.CO;2-O

M3 - Article

AN - SCOPUS:0033060734

VL - 13

SP - 525

EP - 533

JO - Rapid Communications in Mass Spectrometry

JF - Rapid Communications in Mass Spectrometry

SN - 0951-4198

IS - 6

ER -