Stability of membrane bound reactions.
We present a novel approach to the dynamics of reactions of diffusing chemical species with species fixed in space, e.g., by binding to a membrane. The nondiffusing reaction partners are clustered in areas with a diameter smaller than the diffusion length of the diffusing partner. The activated fraction of the fixed species determines the size of an active subregion of the cluster. Linear stability analysis reveals that diffusion is one of the major determinants of the stability of the dynamics. We illustrate the model concept with Ca2+ dynamics in living cells, which has release channels as fixed reaction partners. Our results suggest that spatial and temporal structures in intracellular Ca2+ dynamics are caused by fluctuations due to the small number of channels per cluster.
Thul
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Hahn-Meitner Institut, Abteilung Theorie, Glienicker Strasse 100, D-14109 Berlin, Germany.
Falcke
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D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism; D020013:Calcium Signaling; D002462:Cell Membrane / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism; D053496:Inositol 1,4,5-Trisphosphate Receptors; D007295:Inositol Phosphates / Q000378:metabolism; D008954:Models, Biological; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism
D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D007295:Inositol Phosphates; D018160:Receptors, Cytoplasmic and Nuclear; D002118:Calcium