Mechanism of Proton Transfer in Short Protonated Oligopeptides. 1. N-Methylacetamide and N2-Acetyl-N1-methylglycinamide

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F03%3A00008940" target="_blank" >RIV/00216224:14310/03:00008940 - isvavai.cz</a>

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Mechanism of Proton Transfer in Short Protonated Oligopeptides. 1. N-Methylacetamide and N2-Acetyl-N1-methylglycinamide

Popis výsledku v původním jazyce

A study of proton transfer in models of a single peptide unit (N-methylacetamide) and diamide (N2-acetyl-N1-methylglycinamide) as well as the influence of a single water molecule on proton transfer is presented here. Three proton pathways in protonated N-methylacetamide are considered: isomerization, inversion, and 1,3-proton shift. The isomerization step exhibits the lowest energy barrier. When a single water molecule was added, no significant influence on proton isomerization was observed. In the diamide model, the isomerization-jump mechanism of proton transfer along diamide carbonyl oxygens was inspected, and the proton isomerization steps were found to be the most energy-demanding processes (~17 kcal mol-1). The presence of a single water moleculeleads to a different, lower-energy-barrier proton-transfer mechanism with proton exchange. The highest energy barrier is only 7.6 kcal mol-1. Possible competing pathways are also discussed.

Název v anglickém jazyce

Mechanism of Proton Transfer in Short Protonated Oligopeptides. 1. N-Methylacetamide and N2-Acetyl-N1-methylglycinamide

Popis výsledku anglicky

A study of proton transfer in models of a single peptide unit (N-methylacetamide) and diamide (N2-acetyl-N1-methylglycinamide) as well as the influence of a single water molecule on proton transfer is presented here. Three proton pathways in protonated N-methylacetamide are considered: isomerization, inversion, and 1,3-proton shift. The isomerization step exhibits the lowest energy barrier. When a single water molecule was added, no significant influence on proton isomerization was observed. In the diamide model, the isomerization-jump mechanism of proton transfer along diamide carbonyl oxygens was inspected, and the proton isomerization steps were found to be the most energy-demanding processes (~17 kcal mol-1). The presence of a single water moleculeleads to a different, lower-energy-barrier proton-transfer mechanism with proton exchange. The highest energy barrier is only 7.6 kcal mol-1. Possible competing pathways are also discussed.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

CH - Jaderná a kvantová chemie, fotochemie

OECD FORD obor

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Projekt

<a href="/cs/project/LN00A016" target="_blank" >LN00A016: BIOMOLEKULÁRNÍ CENTRUM</a><br>

Návaznosti

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

Rok uplatnění

2003

Kód důvěrnosti údajů

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

Název periodika

J. Phys. Chem. A

ISSN

1089-5639

e-ISSN

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Svazek periodika

107

Číslo periodika v rámci svazku

30

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

8

Strana od-do

5789-5797

Kód UT WoS článku

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EID výsledku v databázi Scopus

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