Abstract
Recycling of fructose 6-phosphate and fructose 1,6-bisphosphate in the rat liver under gluconeogenic and glycolytic conditions was investigated with a computer model containing representations of the kinetic properties of phosphofructokinase and fructose 1,6-bisphosphatase under realistic physiological conditions. The two enzyme submodels were constructed from data for the isolated enzymes in vitro by formal optimization. Tissue metabolite concentrations were corrected for cytosolic/mitochondrial compartmentation and effects of chelation and protonation equilibria. This model, which mostly considers the behavior of livers from starved rats, predicts negligible recycling under physiologically realistic conditions. Metabolic regulation of fructose 6-phosphate, the magnesium ion concentration and the distribution of adenine nucleotides appear to prevent operation of a 'futile cycle' in vivo. Rate-limiting chemical species were identified by sensitivity analysis.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.