A novel mechanism of proton transfer in protonated peptides
Jazyk angličtina Země Spojené státy americké Médium print
Typ dokumentu časopisecké články, práce podpořená grantem
PubMed
14599203
DOI
10.1021/ja035800z
Knihovny.cz E-zdroje
- MeSH
- glycin analogy a deriváty chemie MeSH
- konformace proteinů MeSH
- peptidy chemie MeSH
- protony MeSH
- termodynamika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- glycin MeSH
- N-acetylglycyl-N'-methylglycinamide MeSH Prohlížeč
- peptidy MeSH
- protony MeSH
The study presents quantum-chemical calculations on proton transfer in protonated N-acetylglycyl-N1-methylglycinamide (AGA) as a short oligopeptide model. All calculations employ the B3LYP functional and the 6-31++G** basis set. Two different mechanisms of proton transfer are discussed. The rate-determining step of the first mechanism exhibits an energy barrier of about 17.7 kcal mol-1, and it is represented by an isomerization of the proton around the double bond of the carbonyl group. The second mechanism is based on the large conformational flexibility of AGA, where all carbonyl oxygens cooperate. The rate-determining step of this mechanism exhibits an energy barrier of only 8.3 kcal mol-1.
Citace poskytuje Crossref.org
Influence of stereochemistry on proton transfer in protonated tripeptide models
