Time behaviour of the modifier involved in the general mechanism of Botts and Morales assuming rapid equilibrium in the modifier bindings

Varón, R.; García-Moreno, Manuela; Amo, Montserrat del; Valero, Edelmira; Garcı́a-Sevilla, Francisco; García‐Molina, Francisco

doi:10.1007/s10910-005-4530-9

Cited by 2 publications

(1 citation statement)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The major differences among the contributions of these authors are the set of simplifying assumptions made about the steady state reached by the enzyme-catalyzed reaction system [20]. However, to date, there is still a lack of a complete analysis about the steady state kinetics of the general modifier mechanism of Botts and Morales without any simplifying assumptions.…”

Section: Introductionmentioning

confidence: 99%

Kinetic behavior of the general modifier mechanism of Botts and Morales with non-equilibrium binding

Chen

Liu

Qian

et al. 2012

Journal of Theoretical Biology

View full text Add to dashboard Cite

In this paper, we perform a complete analysis of the kinetic behavior of the general modifier mechanism of Botts and Morales in both equilibrium steady states and non-equilibrium steady states (NESS). Enlightened by the non-equilibrium theory of Markov chains, we introduce the net flux into discussion and acquire an expression of product rate in NESS, which has clear biophysical significance. Up till now, it is a general belief that being an activator or an inhibitor is an intrinsic property of the modifier. However, we reveal that this traditional point of view is based on the equilibrium assumption. A modifier may no longer be an overall activator or inhibitor when the reaction system is not in equilibrium. Based on the regulation of enzyme activity by the modifier concentration, we classify the kinetic behavior of the modifier into three categories, which are named hyperbolic behavior, bellshaped behavior, and switching behavior, respectively. We show that the switching phenomenon, in which a modifier may convert between an activator and an inhibitor when the modifier concentration varies, occurs only in NESS. Effects of drugs on the Pgp ATPase activity, where drugs may convert from activators to inhibitors with the increase of the drug concentration, are taken as a typical example to demonstrate the occurrence of the switching phenomenon.

show abstract

Section: Introductionmentioning

confidence: 99%