Glycogen phosphorylase
Glycogen phosphorylase (GP) is a dimeric enzyme that catalyses the reaction in which the terminal glucose residue from a glycogen chain is phosphorylated and cleaved from the chain, releasing it as Glc1P.
Chemical equation
![Glycogen + Pi \rightleftharpoons Glucose + Glc1P](/wiki/images/math/b/1/0/b1095aefcda3789c2ca75d47566b6bb4.png)
Rate equation
![\frac{K_{cat,r}[GP]_a n \frac{[Pi]}{K_{r,Pi}} \left( 1 + \frac{[Pi]}{K_{r,Pi}} + \frac{[Glc1P]}{K_{r,Glc1P}} \right)^{n-1} }{\left( 1 + \frac{[Pi]}{K_{r,Pi}} + \frac{[Glc1P]}{K_{r,Glc1P}} \right)^n + L_u \left( 1 + \frac{[Pi]}{K_{u,Pi}} + \frac{[Glc1P]}{K_{u,Glc1P}} \right)^n \left( \frac{1 + \frac{[Glc6P]}{K_{u,Glc6P}}}{1 + \frac{[AMP]}{K_{r,AMP}} + \frac{[Glc6P]}{K_{r,Glc6P}}} \right)^n } + \frac{K_{cat,r}[GP]_a n \frac{[Pi]}{K_{r,Pi}} \left( 1 + \frac{[Pi]}{K_{r,Pi}} + \frac{[Glc1P]}{K_{r,Glc1P}} \right)^{n-1} }{\left( 1 + \frac{[Pi]}{K_{r,Pi}} + \frac{[Glc1P]}{K_{r,Glc1P}} \right)^n + L_u \left( 1 + \frac{[Pi]}{K_{u,Pi}} + \frac{[Glc1P]}{K_{u,Glc1P}} \right)^n \left( \frac{1 + \frac{[AMP]}{K_{t,AMP}} \frac{[Glc6P]}{K_{u,Glc6P}}}{1 + \frac{[AMP]}{K_{r,AMP}} + \frac{[Glc6P]}{K_{r,Glc6P}}} \right)^n \left( 1 + \frac{[ATP]}{K_{t,ATP}} \right) }](/wiki/images/math/d/6/3/d6385e4a8c1d4ee2fe07b04a5c4f2fc6.png)