Are cysteines present at the active site of glycogen phosphorylase?
Periodate and the anions of the transitional elements inactivate glycogen phosphorylase with resolution of the coenzyme from the active site. The effects of the ionic strength and pH of the incubation mixture on the rate of inactivation allow to discriminate between the actions of these chemicals, suggesting that they recognize different regions at the enzyme active site. This conclusion is in agreement with the identification of cysteine as the target amino acid for the inactivation by periodate while arginine was reported to be responsible for the vanadate mediated inactivation.
D001120:Arginine / Q000032:analysis; D001665:Binding Sites; D003545:Cysteine / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D009994:Osmolar Concentration; D006005:Phosphorylases / Q000032:analysis*; D014414:Tungsten / Q000494:pharmacology; D017973:Tungsten Compounds
D017973:Tungsten Compounds; D001120:Arginine; D006005:Phosphorylases; D003545:Cysteine; C045951:tungstate; D014414:Tungsten