Parameters in the models.

a)according to the measured ratio of the B cell nucleus volume VN to the B cell cytosol volume VC: [42].b)pseudo first order reaction; this coefficient determines the relative time scale.c)estimated in [40] (online supplementary material) based on [64],[65], [66].d)The SFK and BCR phosphorylation takes place at the membrane. The experimental data are scarce and provide only the coefficients of phosphorylation referred to the molar concentrations of kinase, which is not adequate for description of the processes on the membrane.e)the value of c0 reflects the assumption that the activity of the unphosphorylated kinase is 100 times smaller than the unphosphorylated kinase; in [40] the ratio of unphosphorylated to phosphorylated kinase activity is assumed to be equal to 0.05.f)the receptor surface density estimated basing on the number of receptors 2.5×105 given in [63] and the surface of cell membrane S of radius 500 is approximately 500/.g)Faeder et al. estimated the number of available Lyn kinase molecules as 2.8×104[67] The remaining Lyn is in its inactive, closed conformation in which kinase domain is inaccessible due to the intramolecular binding. Assuming that Fyn and Blk are present in a similar quantities as Lyn, the total amount of available SFK would be of order 105. We are not giving here the molar density of SFK. As discussed SFK occupy only a small fraction of cell volume, thus the molar concentration referred to whole cell volume is a misleading quantity.