Open AccessA Cycle Of Enzymatic Reactions With Some Properties Of Neuronal Circuits
Author(s) -
Jan Sielewiesiuk
Publication year - 2015
Publication title -
annales universitatis mariae curie-skłodowska. sectio aaa, physica
Language(s) - English
Resource type - Journals
eISSN - 2300-7559
pISSN - 0137-6861
DOI - 10.1515/physica-2015-0005
Subject(s) - bistability , reagent , demethylation , allosteric regulation , chemistry , enzyme , methylation , thermodynamics , physics , biochemistry , quantum mechanics , gene expression , dna methylation , gene
A cycle of four methylation and four demethylation reactions with repression or allosteric inhibition of enzymes is considered. The corresponding dynamical system is characterised by two parameters: the sum of reagent concentrations (C) and the ratio of rate constants of forward and backward reactions (k). In a symmetrical case (k=1) the system has a unique equilibrium. At C>4 the equilibrium is unstable and the system has oscillatory solutions. At k essentially different from 1, the system becomes excitable or behaves as a bistable trigger.