Search results for "Futile cycle"

showing 3 items of 3 documents

Sustained oscillations in the MAP kinase cascade.

2016

Abstract The MAP kinase cascade is a network of enzymatic reactions arranged in layers. In each layer occurs a multiple futile cycle of phosphorylations. The fully phosphorylated substrate then serves as an enzyme for the layer below. This paper focuses on the existence of parameters for which Hopf bifurcations occur and generate periodic orbits. Furthermore it is explained how geometric singular perturbation theory allows to generalize results from simple models to more complex ones.

0301 basic medicineStatistics and ProbabilitySingular perturbationDynamical systems theoryMolecular Networks (q-bio.MN)Dynamical Systems (math.DS)MAP kinase cascadeGeneral Biochemistry Genetics and Molecular BiologyQuantitative Biology::Subcellular Processes03 medical and health sciencessymbols.namesakeSimple (abstract algebra)Classical Analysis and ODEs (math.CA)FOS: MathematicsQuantitative Biology - Molecular NetworksSustained oscillationsMathematics - Dynamical SystemsHopf bifurcationPhysics030102 biochemistry & molecular biologyGeneral Immunology and MicrobiologyFutile cycleApplied MathematicsQuantitative Biology::Molecular NetworksGeneral Medicine030104 developmental biologyClassical mechanicsMathematics - Classical Analysis and ODEsModeling and SimulationFOS: Biological sciencessymbolsPeriodic orbitsGeneral Agricultural and Biological SciencesMathematical biosciences
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Ethanol cycle in an ethanologenic bacterium

2002

AbstractA novel redox cycle is suggested, performing interconversion between acetaldehyde and ethanol in aerobically growing ethanologenic bacterium Zymomonas mobilis. It is formed by the two alcohol dehydrogenase (ADH) isoenzymes simultaneously catalyzing opposite reactions. ADH I is catalyzing acetaldehyde reduction. The local reactant ratio at its active site probably is shifted towards ethanol synthesis due to direct channeling of NADH from glycolysis. ADH II is oxidizing ethanol. The net result of the cycle operation is NADH shuttling from glycolysis to the membrane respiratory chain, and ensuring flexible distribution of reducing equivalents between the ADH reaction and respiration.

NADH channelingBiophysicsRespiratory chainBiochemistryZymomonas mobilischemistry.chemical_compoundStructural BiologyGeneticsGlycolysisEthanol metabolismMolecular BiologyAlcohol dehydrogenaseZymomonasEthanolEthanolbiologyFutile cycleRespirationZymomonas mobilisAlcohol dehydrogenaseAcetaldehydeCell BiologyNADbiology.organism_classificationAerobiosisIsoenzymeschemistryBiochemistryFutile cycleChemostatbiology.proteinOxidation-Reductionhormones hormone substitutes and hormone antagonistsFEBS Letters
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A proof of bistability for the dual futile cycle

2014

Abstract The multiple futile cycle is an important building block in networks of chemical reactions arising in molecular biology. A typical process which it describes is the addition of n phosphate groups to a protein. It can be modelled by a system of ordinary differential equations depending on parameters. The special case n = 2 is called the dual futile cycle. The main result of this paper is a proof that there are parameter values for which the system of ODE describing the dual futile cycle has two distinct stable stationary solutions. The proof is based on bifurcation theory and geometric singular perturbation theory. An important entity built of three coupled multiple futile cycles is…

Singular perturbationBistabilityFutile cycleMolecular Networks (q-bio.MN)Quantitative Biology::Molecular NetworksApplied MathematicsGeneral EngineeringOdeDynamical Systems (math.DS)General MedicineDual (category theory)Computational MathematicsBifurcation theoryMathematics - Classical Analysis and ODEsFOS: Biological sciencesOrdinary differential equationClassical Analysis and ODEs (math.CA)FOS: MathematicsApplied mathematicsQuantitative Biology - Molecular NetworksMathematics - Dynamical SystemsSpecial caseGeneral Economics Econometrics and FinanceAnalysisMathematicsNonlinear Analysis: Real World Applications
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