Sneyd, Dufour, 2002
Model Structure
Oscillations and waves in the concentration of free intracellular calcium ions (Ca2+) are seen in many cell types and are known to be an important intra- and intercellular signalling system. It is therefore of interest to determine the mechanisms underlying such complex dynamic behaviour. One of the most important of these mechanisms is the inositol triphosphate receptor (IPR), which also functions as a Ca2+ channel. Models of the IPR play a central role in models of Ca2+ oscillations and waves. However, many models of this receptor do not agree with recent experimental data on the dynamic responses of the receptor.
In their 2002 dynamic model of the type-2 IPR, which is based on dynamic and steady-state experimental data, James Sneyd and Jean-Francois Dufour demonstrate that Ca2+ binds to the receptor using saturating, not mass-action kinetics. Their model is similar to the Michaelis-Menten model of an enzyme-catalysed reaction (see the figure below). The model assumes that the binding of IP3 (denoted by p in the diagram below) and Ca2+ is sequential , not independent, so Ca2+ can bind to the activating site only after IP3 has bound.
The complete original paper reference is cited below:
A dynamic model of the type-2 inositol triphosphate receptor, James Sneyd and Jean-Francois Dufour, 2002, Proceedings of the National Academy of Sciences , 99, 2398-2403. (A PDF of the article is available to subscribers of the PNAS website.) PubMed ID: 11842185
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| A simplified diagram of the IPR model, where R represents the free receptor, O is the open state of the channel, A is the activated state of the channel and I1, I2, and S are three inactive states. |