Structural highlights
Function
PYGM_RABIT Phosphorylase is an important allosteric enzyme in carbohydrate metabolism. Enzymes from different sources differ in their regulatory mechanisms and in their natural substrates. However, all known phosphorylases share catalytic and structural properties.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Glucopyranosylidene spirothiohydantoin (TH) has been identified as a potential inhibitor of both muscle and liver glycogen phosphorylase b (GPb) and a (GPa) and shown to diminish liver GPa activity in vitro. Kinetic experiments reported here show that TH inhibits muscle GPb competitively with respect to both substrates phosphate (K(i)=2.3 microM) and glycogen (K(i)=2.8 microM). The structure of the GPb-TH complex has been determined at a resolution of 2.26 A and refined to a crystallographic R value of 0.193 (R(free)=0.211). The structure of GPb-TH complex reveals that the inhibitor can be accommodated in the catalytic site of T-state GPb with very little change of the tertiary structure, and provides a basis of understanding potency and specificity of the inhibitor. The glucopyranose moiety makes the standard hydrogen bonds and van der Waals contacts as observed in the glucose complex, while the rigid thiohydantoin group is in a favourable electrostatic environment and makes additional polar contacts to the protein.
Kinetic and crystallographic studies of glucopyranosylidene spirothiohydantoin binding to glycogen phosphorylase B.,Oikonomakos NG, Skamnaki VT, Osz E, Szilagyi L, Somsak L, Docsa T, Toth B, Gergely P Bioorg Med Chem. 2002 Feb;10(2):261-8. PMID:11741774[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Oikonomakos NG, Skamnaki VT, Osz E, Szilagyi L, Somsak L, Docsa T, Toth B, Gergely P. Kinetic and crystallographic studies of glucopyranosylidene spirothiohydantoin binding to glycogen phosphorylase B. Bioorg Med Chem. 2002 Feb;10(2):261-8. PMID:11741774
