Hilfe Wegweiser Impressum Kontakt Einloggen





Quantum chemical modeling of the kinetic isotope effect of the carboxylation step in RuBisCO


Götze,  J. P.
Research Department Thiel, Max-Planck-Institut für Kohlenforschung, Max Planck Society;

Externe Ressourcen
Es sind keine Externen Ressourcen verfügbar
Volltexte (frei zugänglich)
Es sind keine frei zugänglichen Volltexte verfügbar
Ergänzendes Material (frei zugänglich)
Es sind keine frei zugänglichen Ergänzenden Materialien verfügbar

Götze, J. P., & Saalfrank, P. (2012). Quantum chemical modeling of the kinetic isotope effect of the carboxylation step in RuBisCO. Journal of Molecular Modeling, 18(5), 1877-1883. doi:10.1007/s00894-011-1207-0.

Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO), the most important enzyme for the assimilation of carbon into biomass, features a well-known isotope effect with regards to the CO2 carbon atom. This kinetic isotope effect α = k12/k13 for the carboxylation step of the RuBisCO reaction sequence, and its microscopic origin, was investigated with the help of cluster models and quantum chemical methods [B3LYP/6-31G(d,p)]. We use a recently proposed model for the RuBisCO active site, in which a water molecule remains close to the reaction center during carboxylation of ribulose-1,5-bisphosphate [B. Kannappan, J.E. Gready, J. Am. Chem. Soc. 130 (2008), 15063]. Alternative active-site models and/or computational approaches were also tested. An isotope effect alpha for carboxylation is found, which is reasonably close to the one measured for the overall reaction, and which originates from a simple frequency shift of the bending vibration of 12CO2 compared to 13CO2. The latter is the dominant mode for the product formation at the transition state.