Modelling the reaction mechanism of ribulose-1,5-bisphosphate carboxylase/oxygenase and consequences for kinetic parameters

Guillaume Tcherkez*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

58 Citations (Scopus)

Abstract

Although ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) was discovered nearly 60 years ago, the associated chemical mechanism of the reaction is still incompletely understood. The catalytic cycle consists of four major steps: ribulose-1,5-bisphosphate binding, enolization, CO2 or O2 addition and hydration, and cleavage of the intermediate. The use of individual rate constants for these elemental steps yields mathematical expressions for usual kinetic constants (kcat, Km), CO2 versus O2 specificity (Sc/o) as well as other chemical parameters such as the 12C/13C isotope effect. That said, most of them are not simple and thus the interpretation of experimental and observed values of kcat, Km and Sc/o may be more complicated than expected. That is, Rubisco effective catalysis depends on several kinetic parameters that are influenced by both the biological origin and the cellular medium (which, in turn, can vary with environmental conditions). In this brief review, we present the basic model of Rubisco kinetics and describe how subtle biochemical changes (which may have occurred along Evolution) can easily modify Rubisco catalysis. The chemical mechanism of Rubisco is at the heart of photosynthetic metabolism since it dictates the rate of carboxylation. Here, advantage is taken of chemical formalism to give general equations describing carboxylation velocity, specificity and isotope effects. The limits of these and uncertainties on intrinsic chemical events are discussed so as to appreciate possibilities of optimization.

Original languageEnglish
Pages (from-to)1586-1596
Number of pages11
JournalPlant, Cell and Environment
Volume36
Issue number9
DOIs
Publication statusPublished - Sept 2013
Externally publishedYes

Fingerprint

Dive into the research topics of 'Modelling the reaction mechanism of ribulose-1,5-bisphosphate carboxylase/oxygenase and consequences for kinetic parameters'. Together they form a unique fingerprint.

Cite this