The preferred reaction path for the oxidation of methanol by PQQ-containing methanol dehydrogenase: addition-elimination versus hydride-transfer mechanism.
The catalytic oxidation of methanol to formaldehyde by pyrroloquinoline quinone (PQQ)-containing methanol dehydrogenase (MDH) was investigated at density functional B3LYP level. The still controversial addition-elimination and hydride-transfer reaction mechanisms were analysed. Computations performed in the gas phase and in the protein environment indicated that both suggested reaction sequences involve very high activation barriers. In this situation, the reactions should have scarce probability to occur and the preference for one of the two paths cannot be stated. Here, we will show how some corrections to the successive steps in the addition-elimination mechanism can sensibly decrease the activation barriers height, making possible the determination of the MDH-preferred catalytic path.
Leopoldini
Monica
M
Dipartimento di Chimica and Centro di Calcolo ad Alte Prestazioni per Elaborazioni, Parallele e Distribuite-Centro d'Eccellenza MIUR, Universita' della Calabria, 87030 Arcavacata di Rende (CS), Italy.
Russo
Nino
N
Toscano
Marirosa
M
D000429:Alcohol Oxidoreductases / Q000737:chemistry* / Q000378:metabolism*; D001665:Binding Sites; D000432:Methanol / Q000378:metabolism*; D008956:Models, Chemical; D008958:Models, Molecular; D010084:Oxidation-Reduction; D045542:PQQ Cofactor / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation
D045542:PQQ Cofactor; D000429:Alcohol Oxidoreductases; C019641:alcohol dehydrogenase (acceptor); D000432:Methanol