| |
Reaction
Name | Pathway Name /
Pathway No. | Kf | Kb | Kd | tau | Reagents |
| 1 | CaM_bind_PDE1 | AC
Pathway No. 269 | 719.982
(uM^-1 s^-1) | 5
(s^-1) | Kd(bf) = 0.0069(uM) | - | Substrate:
PDE1
CaM-Ca4
Products:
CaM.PDE1
|
| For olf epi PDE1, affinity is 7 nM. Assume same for brain. Reaction should be pretty fast. Assume kb = 5/sec. Then kf = 5 / (0.007 * 6e5) = 1.2e-3 | | 2 | CaM-bind-AC1 | AC
Pathway No. 269 | 49.9997
(uM^-1 s^-1) | 1
(s^-1) | Kd(bf) = 0.02(uM) | - | Substrate:
CaM-Ca4
AC1
Products:
AC1-CaM
|
| Half-max at 20 nM CaM (Tang et al JBC 266:13 8595-8603 1991 kb/kf = 20 nM = 12000 #/cell so kf = kb/12000 = kb * 8.333e-5 | | 3 | dephosph-AC2 | AC
Pathway No. 269 | 0.1
(s^-1) | 0
(s^-1) | - | - | Substrate:
AC2*
Products:
AC2
|
| Random rate. | | 4 | dephosph-PDE | AC
Pathway No. 269 | 0.01
(s^-1) | 0
(s^-1) | - | - | Substrate:
cAMP-PDE*
Products:
cAMP-PDE
|
| The rates for this are poorly constrained. In adipocytes (probably a different PDE) the dephosphorylation is complete within 15 min, but there are no intermediate time points so it could be much faster. Identity of phosphatase etc is still unknown. | | 5 | cAMP_diffusion | AC
Pathway No. 269 | 300
(s^-1) | 5.4
(s^-1) | Not applicable** | - | Substrate:
cAMP
Products:
cAMP_in_dend
|
| Represents diffusion, from a volume of 9e-20 to 5e-18. Assuming neck dimensions of 0.1 x 0.1 microns, this works out to a diffusion const of about 270 um^2/sec, which is pretty conservative. It is what cAMP does in frog cilia. |
** This is a trasport reation between compartments of different volumes. Therefore Kd is not applicable. Please Note Kf, Kb units are in number of molecules instead of concentration
and 
color.
indicates that ordering is done according to ascending or descending order.