| Titre : | Kinetic model for the reversible hydration of carbon dioxide catalyzed by human carbonic anhydrase II (2010) |
| Auteurs : | F. Larachi, Auteur |
| Type de document : | Article : texte imprimé |
| Dans : | Industrial & engineering chemistry research (Vol. 49 N° 19, Octobre 2010) |
| Article en page(s) : | pp. 9095–9104 |
| Note générale : | Chimie industrielle |
| Langues : | Anglais |
| Tags : | 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 |
