Free Energy of ATP hydrolysis manipulates the cellular calcium signals

In living cells, oscillation of the concentration of cytosolic Ca2+ is an important and pervasive signal for the intercellular and intracellular information conduction. To generate the oscillation, the hydrolysis of ATP is always needed. Many recent studies show that both ATP molecules themselves and the free energy by ATP hydrolysis play significant role in the biochemical process involving ATP hydrolysis. To verify the prediction, we consider the role of ATP molecules and their hydrolysis in a classic one-pool model of Ca2+ oscillation. Our results show that the available Gibbs free energy of ATP hydrolysis {\DeltaG}, which measures the "distance" of a reaction to its equilibrium state, is another important regulatory factor of the oscillation system besides the concentration of ATP. Furthermore, our model suggest a rudimental prediction of how the oscillation system changes in an aging cell, such as the decrease of the amplitude and the increase of the least {\DeltaG} required for the oscillation.