Radical Reactions Affecting Polar Groups in Threonine Peptide Ions

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388963%3A_____%2F17%3A00477515" target="_blank" >RIV/61388963:_____/17:00477515 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1021/acs.jpcb.7b04661" target="_blank" >http://dx.doi.org/10.1021/acs.jpcb.7b04661</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.jpcb.7b04661" target="_blank" >10.1021/acs.jpcb.7b04661</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Radical Reactions Affecting Polar Groups in Threonine Peptide Ions

Popis výsledku v původním jazyce

Peptide cation-radicals containing the threonine residue undergo radical induced dissociations upon collisional activation and photon absorption in the 210-400 nm range. Peptide cation-radicals containing a radical defect at the N-terminal residue, [(center dot)Ala-Thr-Ala-Arg+H](+), were generated by electron transfer dissociation (ETD) of peptide dications and characterized by UV vis photodissociation action spectroscopy combined with time-dependent density functional theory (TD-DFT) calculations of absorption spectra, including thermal vibronic band broadening. The acute spectrum of [(center dot)Ala-Thr-Ala-Arg+H](+) ions was indicative of the canonical structure of an N-terminally deaminated radical whereas isomeric structures differing in the position of the radical defect and amide bond geometry were excluded. This indicated that exothermic electron transfer to threonine peptide ions did not induce radical isomerizations in the fragment cation-radicals. Several isomeric structures, ion molecule complexes, and transition states for isomerizations and dissociations were generated and analyzed by DFT and Moller Plesset perturbational ab initio calculations to aid interpretation of the major dissociations by loss of water, hydroxyl radical, C3H6NO center dot, C3H7NO, and backbone cleavages. Born-Oppenheimer molecular dynamics (BOMD) in combination with DFT gradient geometry optimizations and intrinsic reaction coordinate analysis were used to search for low-energy cation-radical conformers and transition, states. BOMD was also employed to analyze the reaction trajectory for loss of water from ion molecule complexes.

Název v anglickém jazyce

Radical Reactions Affecting Polar Groups in Threonine Peptide Ions

Popis výsledku anglicky

Peptide cation-radicals containing the threonine residue undergo radical induced dissociations upon collisional activation and photon absorption in the 210-400 nm range. Peptide cation-radicals containing a radical defect at the N-terminal residue, [(center dot)Ala-Thr-Ala-Arg+H](+), were generated by electron transfer dissociation (ETD) of peptide dications and characterized by UV vis photodissociation action spectroscopy combined with time-dependent density functional theory (TD-DFT) calculations of absorption spectra, including thermal vibronic band broadening. The acute spectrum of [(center dot)Ala-Thr-Ala-Arg+H](+) ions was indicative of the canonical structure of an N-terminally deaminated radical whereas isomeric structures differing in the position of the radical defect and amide bond geometry were excluded. This indicated that exothermic electron transfer to threonine peptide ions did not induce radical isomerizations in the fragment cation-radicals. Several isomeric structures, ion molecule complexes, and transition states for isomerizations and dissociations were generated and analyzed by DFT and Moller Plesset perturbational ab initio calculations to aid interpretation of the major dissociations by loss of water, hydroxyl radical, C3H6NO center dot, C3H7NO, and backbone cleavages. Born-Oppenheimer molecular dynamics (BOMD) in combination with DFT gradient geometry optimizations and intrinsic reaction coordinate analysis were used to search for low-energy cation-radical conformers and transition, states. BOMD was also employed to analyze the reaction trajectory for loss of water from ion molecule complexes.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

<a href="/cs/project/GA17-24155S" target="_blank" >GA17-24155S: Mapování konformačního prostoru krátkých peptidů pokročilými kvantově-chemickými a solvatačními metodami: klíč k pochopení struktury proteinů?</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Physical Chemistry B

ISSN

1520-6106

e-ISSN

—

Svazek periodika

121

Číslo periodika v rámci svazku

27

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

13

Strana od-do

6557-6569

Kód UT WoS článku

000405764000012

EID výsledku v databázi Scopus

2-s2.0-85024928949