How do enzyme activities control metabolite concentrations?

An additional theorem in the theory of metabolic control

Authors

  • Hans V. WESTERHOFF,

    1. Laboratory of Molecular Biology, National Institute of Arthritis, Diabetes and Digestive and Kidney Diseases, National Institutes of Health. 9000 Rockville Pike, Bethesda, Maryland, USA 20205
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  • Yi-Der CHEN

    1. Laboratory of Molecular Biology, National Institute of Arthritis, Diabetes and Digestive and Kidney Diseases, National Institutes of Health. 9000 Rockville Pike, Bethesda, Maryland, USA 20205
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  • Remark: We shall assume throughout that both C and ∈ can be defined. Cases with zero reaction rates or concentrations are formally excluded. For these cases alternative theorems are easily formulated.

Abstract

A simple theorem is derived relating the extent to which enzymes in a metabolic pathway control the steady-state concentration of metabolites to the kinetic properties of those enzymes. The theorem gives insight into the mechanism by which the concentration of a second messenger is controlled by the enzymes that form and degrade it, and provides an alternative to the ‘cross-over theorem’

Enzymes
 

Adenylate cyclase (EC 4.6.1.1)

 

phosphodiesterase (EC 3.1.4.1)

 

AMP deaminase (EC 3.5.4.6)

Ancillary