Before revision:  Each subunit in both configurations has one IP_3 binding site, together with one activating and one inhibitory Ca^{2+ the well-known Monod-Wyman-Changeux allosteric model, we construct our model from the subunit level to the channel level  .
After revision:  Each subunit in both configurations has one IP_3 binding site, together with one activating and one inhibitory Ca^{2+ the well-known Monod-Wyman-Changeux allosteric model, we construct our model from the subunit level to the channel levelXenopus .