|
Enter a Search String | | Special character and space not allowed in the query term.
Search string should be at least 2 characters long. |
Molecule Parameter List for GAP | The statistics table lists the distribution of a molecule acting either as a substrate, product, enzyme or as a molecule within the network.
The text color of a molecule is highlighted by  color. | | Statistics |
Accession and Pathway Details | |
GAP acting as a Molecule in MAPK-bistability-fig1c Network
| Name | Accession Name | Pathway Name | Initial Conc.
(uM) | Volume
(fL) | Buffered | | GAP | MAPK-bistability
-fig1c
Accession No. : 35 | Ras
Pathway No. : 184 | 0.002 | 1000 | No | | GTPase-activating proteins. See Boguski and McCormick 1993 Nature 366:643-654 Turn off Ras by helping to hydrolyze bound GTP. This one is probably NF1, ie., Neurofibromin as it is inhibited by AA and lipids, and expressed in neural cells. p120-GAP is also a possible candidate, but is less regulated. Both may exist at similar levels. See Eccleston et al JBC 268(36) pp27012-19 Level=.002 |
GAP acting as an Enzyme in MAPK-bistability-fig1c Network
Enzyme Molecule /
Enzyme Activity | Accession Name | Pathway Name | Km (uM) | kcat (s^-1) | Ratio | Enzyme Type | Reagents | GAP /
GAP-inact-ras
| MAPK-bistability
-fig1c
Accession No. : 35 | Ras
Pathway No. : 184 | 1.0104 | 10 | 100 | explicit E-S complex | Substrate
GTP-Ras
Product
GDP-Ras
| | From Eccleston et al JBC 268(36)pp27012-19 get Kd < 2uM, kcat - 10/sec From Martin et al Cell 63 843-849 1990 get Kd ~ 250 nM, kcat = 20/min I will go with the Eccleston figures as there are good error bars (10%). The two sets of values are reasonably close. k1 = 1.666e-3/sec, k2 = 1000/sec, k3 = 10/sec (note k3 is rate-limiting) This is one of the rare cases where we have direct info on the k3 being rate-limiting. Hence the ratio I use for the k2:k3 rates is 100 rather than the usual 4. |
GAP acting as a Substrate for an Enzyme in MAPK-bistability-fig1c Network
Enzyme Molecule /
Enzyme Activity | Accession Name | Pathway Name | Km (uM) | kcat (s^-1) | Ratio | Enzyme Type | Reagents | PKC-active /
PKC-inact-GAP | MAPK-bistability
-fig1c
Accession No. : 35 | Shared_Object_
MAPK-bistability
-fig1c
Pathway No. : 179 | 66.6667 | 25 | 4 | explicit E-S complex | Substrate
GAP
Product
GAP*
| | Rate consts are PKC generic rates. This reaction inactivates GAP. The reaction is from the Boguski and McCormick 1993 review in Nature 366:643-654 The phosphorylation Vmax is 6x higher to account for balance of GDP-Ras:GDP-Ras. |
GAP acting as a Product in a reaction in MAPK-bistability-fig1c Network
| Kd is calculated only for second order reactions, like nA+nB <->nC or nA<->nC+nD, where n is number and A,B,C,D are molecules, where as for first order reactions Keq is calculated.
Kd for higher order reaction are not consider. |
| Name | Accession Name | Pathway Name | Kf | Kb | Kd | tau | Reagents | | dephosph-GAP | MAPK-bistability
-fig1c
Accession No. : 35 | Ras
Pathway No. : 184 | 0.1
(s^-1) | 0
(s^-1) | - | - | Substrate
GAP*
Product
GAP
| | Assume a reasonably good rate for dephosphorylating it, 0.1/sec. This fits well with resting levels of active kinase and the degree of activation as well as time-course of turnoff of Ras activation, but data is quite indirect. |
| Database compilation and code copyright (C) 2022, Upinder S. Bhalla and NCBS/TIFR
This Copyright is applied to ensure that the contents of this database remain freely available. Please see FAQ for details. |
|
