Simulation of the detailed regulation of glycolytic oscillation in a heart supernatant preparation

Abstract

Regulation of glycolysis during sustained oscillations has been studies by simulating in detail the experimentally observed behavior of a supernatant fraction from beef heart. This preparation exhibits cyclic oscillations in concentrations of all observed glycolytic intermediates and coenzymes. A model consisting of 57 simultaneous differential equations representing 101 chemical reactions was used to simulate the experimental results. Most of the enzyme sub-models composing this are quite similar to those used for a nonoscillating glycolytic simulation. The differential equations were solved numerically by digital computers. An alternative calculation method, which speeds the process of computation by a factor of 100, was used in the later stages of model construction. Phosphofructokinase, primarily under adenine nucleotide control resulting in pulsed-type variations of active concentrations, causes oscillation in this system, although some other enzymes exert a secondary control. The discrepancies found between experimental and computed behavior suggest presently unknown control mechanisms and areas for further experimentation.