Control of flux and transition time was investigated with a reconstructed rabbit muscle glycolytic system in vitro as an experimental model. The results show agreement with the summation property for the Flux Control Coefficients [Kacser & Burns (1973) Symp. Soc. Exp. Biol. 27, 65-104; Heinrich & Rapoport (1974) Eur. J. Biochem. 42, 89-95]. Control of flux is almost exclusively located at the hexokinase- and phosphofructokinase-catalysed steps, whereas control of transition time is distributed more evenly between the enzymes of the system. The summation value of the Transition Time Control Coefficients is near to -1, suggesting the existence of another Summation Theorem besides that already stated for Flux Control Coefficients. Finally, we study the effect of an external stimulator of the system (fructose 2,6-bisphosphate) on the Control Coefficient profiles. The effect appears to be greater on the Transition Time Control Coefficient distribution than on the Flux Control Coefficients.
Study of the flux and transition time control coefficient profiles in a metabolic system in vitro and the effect of an external stimulator
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N V Torres, R Souto, E Meléndez-Hevia; Study of the flux and transition time control coefficient profiles in a metabolic system in vitro and the effect of an external stimulator. Biochem J 15 June 1989; 260 (3): 763–769. doi: https://doi.org/10.1042/bj2600763
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