Resting free [Ca2+]i (nM) | 81 |
Eq. 3 |
Peak free Δ[Ca2+]i (nM) | 760 |
Eq. 9; Fig. 3B |
Total [calcium] entering (Δ[Catotal]; µM) | 45 |
Eq. 10; Fig 3C |
Absolute extrusion rate Leak intrusion rate | 2.2 × 1011 M–1 s−1
1.77 × 105 s−1
| Fig. 4B × total # Ca2+ ions for resting [Ca2+]I = 81 nM |
Decay rate at 0 [dye] (τ) | 0.110 s |
Fig. 3A |
Volume of model terminal (L) Cytosolic volume (L) | 1.22 × 10–11
1.07 × 10–11
| Cytosolic volume excludes organelle and vesicle structures in the model |
| Dye parameters | |
Fluo-4 Kd/kon/koff
Fmin/Fmax
| 0.44 µM/5 × 108 M–1 s−1/221.5 s−1/750 s−1
0.0232 |
Fig. 1 |
Fluo-5F Kd/kon/koff | 1.49 µM/5 × 108 M–1 s−1/750 s−1 |
Fig. 1 |
| Calcium buffers | |
Calbindin28K concentration Ratio of high to low affinity sites 3:1 ratio high affinity kon1/koff1
3:1 ratio med. affinity kon2/koff2
2:2 ratio high affinity kon1/koff1
2:2 ratio low affinity kon2/koff2
| 15–60 µM 2:2 or 1:3 6.5 × 106 M–1 s−1/2.405 s−1
3.85 × 107 M–1 s−1/44.44 s−1
5.5 × 106 M–1 s−1/2.6 s−1
4.35 × 107 M–1 s−1/35.8 s−1
| Varied in model Varied in model (Nägerl et al., 2000; Schmidt et al., 2012) |
Calmodulin concentration N-terminal kon/off T N-terminal kon/off R C-terminal kon/off T C-terminal kon/off R | 15 – 60 µM 7.7 × 108 M–1 s−1/1.6 × 105 s−1
3.2 × 1010 M–1 s−1/2.2 × 104 s−1
8.4 × 107 M–1 s−1/2.6 × 103 s−1
2.5 × 107 M–1 s−1/6.5 s−1
| Varied in model
Faas et al. (2011; stoichiometry is present with each EF hand lobe showing two sequential on and off rates represented by T and R) |
Syt1 C2A kon/koff
Syt1 C2B kon/koff
| 2 × 108 M–1 s−1/1.2 × 104 s−1
2 × 108 M–1 s−1/8 × 103 s−1
2 × 108 M–1 s−1/2 × 105 s−1
2 × 108 M–1 s−1/4 × 104 s−1
2 × 108 M–1 s−1/4 × 104 s−1
|
Radhakrishnan et al. (2009) |
| Diffusion constants | |
DCa | 223 µm2 s−1 |
Allbritton et al. (1992) |
DFluo-4 | 75 µm2 s−1 |
Kong et al. (2013) |
DFluo-5F | 75 µm2 s−1 |
Kong et al. (2013) |
DCalbindin | 0.2 fraction immobile |
Schmidt et al. (2012) |
| 0.8 fraction mobile, 20 µm2 s−1 |
Schmidt et al. (2012) |