Kinetic model for the reversible hydration of carbon dioxide catalyzed by human carbonic anhydrase II / F. Larachi in Industrial & engineering chemistry research, Vol. 49 N° 19 (Octobre 2010)  

Kinetic model for the reversible hydration of carbon dioxide catalyzed by human carbonic anhydrase II [texte imprimé] / F. Larachi, Auteur . - 2010 . - pp. 9095–9104.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9095–9104

Mots-clés :	Kinetic Hydration carbon dioxide
Résumé :	Four variants of the two-step Ping Pong mechanism for the reversible hydration of carbon dioxide to bicarbonate catalyzed by free human carbonic anhydrase II (HCA II) in solutions were derived and their goodness-of-fit to match measured initial hydration rates tested. The pseudo (i.e., no central complex) random Quad Quad Iso Ping Pong mechanism with one transitory complex was retained which implied a possible competitive intermolecular proton transfer step by the CO2/HCO3− pair with respect to external buffer. The model suggests this role could be emphasized in product inhibition conditions at high bicarbonate/buffer concentration ratios. A 4-parameter kinetic model was derived to complement the existing single- (intra- or intermolecular) limiting-step models for HCA II catalyzed hydration of CO2 in which were accounted for altogether the enzyme isomerization and CO2/HCO3− proton transfer via a [CO2]·[HCO3−] coupling, the CO2/HCO3− proton transfer via [HCO3−]2 and [CO2]·[HCO3−]2 couplings, and an enzyme−substrate transitory complex via [CO2]·[HCO3−]·[Buffer] coupling. This model may prove helpful for analysis of CO2 capture reactor models subject to mixed (intra- or intermolecular) proton-transfer control, intermolecular proton transfer competition by the CO2/HCO3− pair, and large CO2 conversions.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie101338r