MICHAELIS COMPLEX OF FRUCTOSE-2,6-BISPHOSPHATASE

The dynamics of the fructose 6-phosphate/fructose 1,6-bisphosphate cycle was investigated in an open and homogeneous system reconstituted from purified enzymes. In addition to phosphofructokinase and fructose 1,6-bisphosphatase, pyruvate kinase, adenylate kinase and glucose 6-phosphate isomerases are involved. The time evolution of the metabolite concentrations is governed by a set of differential equations which take into account flow processes and enzymic conversions of metabolites. Depending on the experimental parameters stable attractors, multiple states and sustained oscillations occur. The main source of the nonlinear dynamics is the reciprocal effect of AMP on the activities of phosphofructokinase and fructose 1,6-bisphosphatase. States are characterized by the net flow rates of substrates and by the rate of futile substrate cycling. For efficient glycolytic states high ratios between the influx rates of fructose 6-phosphate and fructose 1,6-bisphosphate and between the maximum activities of phosphofructokinase and fructose 1,6-bisphosphatase must be maintained, while for an efficient gluconeogenic mode the reverse must hold. Fructose 2,6-bisphosphate exerts reciprocal effects on the activities of phosphofructokinase and fructose 1,6-bisphosphatase. In dependence on the experimental conditions fructose 2,6-bisphosphate was found either to generate or to extinguish oscillations.

Fructose 2,6-bisphosphate

Fructose 1,6-bisphosphatase

Phosphofructokinase 2

Fructolysis

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Citations (1)

The binding site for pyridoxal 5'-phosphate in fructose 6-phosphate-2-kinase: fructose-2,6-bisphosphatase

Federation Proceedings (1985)

S Kitajima Helmut Thomas K. Uyeda

Pyridoxal 5-Phosphate

Fructose 1,6-bisphosphatase

Pyridoxal phosphate

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Fructose-2,6-Bisphosphate

Simon J. Pilkis

Historical Perspective and Discovery of Fructose-2,6-Bisphosphate. Effects of Fructose-2,6-Bisphosphate on 6-Phosphofructo 1-Kinase and Fructose-1,6-Bisphosphatase. The Sites of Interaction of Fructose-2,6-Bisphosphate and Fructose-1,6-Bisphosphate with Their Target Enzymes: 6-Phosphofructo-1-Kinase and Fructose-1,6-Bisphosphatase. Analogs of Fructose-2,6-Bisphosphate as Activators of 6-Phosphofructo-1-Kinase and Pyrophosphate-Dependent Phosphofructokinase and as Inhibitors of Fructose-1,6-Bisphosphatase. Role of Fructose-2,6-Bisphosphate in the Regulation of Hepatic Carbohydrate Metabolism. Liver 6-Phosphofructo-2-Kinase/Fructose-2,-6-Bisphosphatase. Tertiary Structure Modeling of 6-Phosphofructo-2-Kinase/Fructose-2,6-Bisphosphatase: Structural, Funtional, and Evolutionary Design of Bifunctional Enzyme. Fructose-2,6-Bisphosphate in Extra Hepatic Tissues. The Role of Fructose-2,6-Bisphosphate in Plant Tissues. On The Nature of Fructose-2,6-P2 Metabolizing Enzymes in Plants. Role of Fructose-2,6-P2 in Yeast. Fructose-2,6-Bisphosphate in Primitive Systems. The Importance of Being Bifunctional (with Apologies to Oscar Wilde). Reflections on Future Research on Fructose-2,6-Bisphosphate Metabolism. c. 192 pp., 7x10, 1989, ISBN 0-8493-4795-5.

Fructose 2,6-bisphosphate

Phosphofructokinase 2

Fructose 1,6-bisphosphatase

Fructolysis

Aldolase B

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Citations (11)

Quasi-stationary concentrations of fructose-2,6-bisphosphate in the phosphofructokinase-2/fructose-2,6-bisphosphatase cycle

Biochemical and Biophysical Research Communications (1985)

Matthias Kretschmer Wolfgang Schellenberger Eberhard Hofmann

Fructose 1,6-bisphosphatase

Fructose 2,6-bisphosphate

Phosphofructokinase 2

10.1016/0006-291x(85)91324-5

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Citations (4)

[Functioning of fructose-1,6-bisphosphatase--main enzyme of gluconeogenesis in microorganisms].

PubMed (2004)

Iastrebova Ov

The modern literature data about common characteristics, genetic and molecular-biological properties of main enzyme of gluconeogenesis (fructose-1,6-bisphosphatase) were analyzed. Regulation of fructose-1,6-bisphosphatase activity (stimulation and inhibition) by fructose-1,6-bisphosphate, fructose-2,6-bisphosphate, phosphoenolpyruvate, AMP and by metal ions are discussed. It was concluded that apart from the fact that fructose-1,6-bisphosphatase was intensively investigated, this enzyme from Mollicutes failed to be studied sufficiently.

Fructose 1,6-bisphosphatase

Gluconeogenesis

Fructolysis

Fructose 2,6-bisphosphate

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Citations (1)

Dynamic Structures in the Fructose-6-Phosphate/Fructose' 1,6-Bisphosphatase Cycle

De Gruyter eBooks (1988)

Wolfgang Schellenberger Matthias Kretschmer Klaus Eschrich Eberhard Hofmann

Fructose 1,6-bisphosphatase

Fructolysis