3AMV

ALLOSTERIC INHIBITION OF GLYCOGEN PHOSPHORYLASE A BY A POTENTIAL ANTIDIABETIC DRUG


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.189 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Allosteric inhibition of glycogen phosphorylase a by the potential antidiabetic drug 3-isopropyl 4-(2-chlorophenyl)-1,4-dihydro-1-ethyl-2-methyl-pyridine-3,5,6-tricarbo xylate.

Oikonomakos, N.G.Tsitsanou, K.E.Zographos, S.E.Skamnaki, V.T.Goldmann, S.Bischoff, H.

(1999) Protein Sci. 8: 1930-1945

  • DOI: 10.1110/ps.8.10.1930
  • Primary Citation of Related Structures:  
  • Also Cited By: 1E1Y, 1WV1, 1WV0, 1WUY

  • PubMed Abstract: 
  • The effect of the potential antidiabetic drug (-)(S)-3-isopropyl 4-(2-chlorophenyl)-1,4-dihydro-1-ethyl-2-methyl-pyridine-3,5,6-tricarbox ylate (W1807) on the catalytic and structural properties of glycogen phosphorylase a has been studied. Glycogen ...

    The effect of the potential antidiabetic drug (-)(S)-3-isopropyl 4-(2-chlorophenyl)-1,4-dihydro-1-ethyl-2-methyl-pyridine-3,5,6-tricarbox ylate (W1807) on the catalytic and structural properties of glycogen phosphorylase a has been studied. Glycogen phosphorylase (GP) is an allosteric enzyme whose activity is primarily controlled by reversible phosphorylation of Ser14 of the dephosphorylated enzyme (GPb, less active, predominantly T-state) to form the phosphorylated enzyme (GPa, more active, predominantly R-state). Upon conversion of GPb to GPa, the N-terminal tail (residues 5-22), which carries the Ser14(P), changes its conformation into a distorted 3(10) helix and its contacts from intrasubunit to intersubunit. This alteration causes a series of tertiary and quaternary conformational changes that lead to activation of the enzyme through opening access to the catalytic site. As part of a screening process to identify compounds that might contribute to the regulation of glycogen metabolism in the noninsulin dependent diabetes diseased state, W1807 has been found as the most potent inhibitor of GPb (Ki = 1.6 nM) that binds at the allosteric site of T-state GPb and produces further conformational changes, characteristic of a T'-like state. Kinetics show W1807 is a potent competitive inhibitor of GPa (-AMP) (Ki = 10.8 nM) and of GPa (+1 mM AMP) (Ki = 19.4 microM) with respect to glucose 1-phosphate and acts in synergism with glucose. To elucidate the structural features that contribute to the binding, the structures of GPa in the T-state conformation in complex with glucose and in complex with both glucose and W1807 have been determined at 100 K to 2.0 A and 2.1 A resolution, and refined to crystallographic R-values of 0.179 (R(free) = 0.230) and 0.189 (R(free) = 0.263), respectively. W1807 binds tightly at the allosteric site and induces substantial conformational changes both in the vicinity of the allosteric site and the subunit interface. A disordering of the N-terminal tail occurs, while the loop of chain containing residues 192-196 and residues 43'-49' shift to accommodate the ligand. Structural comparisons show that the T-state GPa-glucose-W1807 structure is overall more similar to the T-state GPb-W1807 complex structure than to the GPa-glucose complex structure, indicating that W1807 is able to transform GPa to the T'-like state already observed with GPb. The structures provide a rational for the potency of the inhibitor and explain GPa allosteric inhibition of activity upon W1807 binding.


    Related Citations: 
    • The Structure of Glycogen Phosphorylase B with an Alkyl-Dihydropyridine- Dicarboxylic Acid Compound, a Novel and Potent Inhibitor
      Zographos, S.E.,Oikonomakos, N.G.,Tsitsanou, K.E.,Leonidas, D.D.,Chrysina, E.D.,Skamnaki, V.T.,Bischoff, H.,Goldman, S.,Schramm, M.,Watson, K.A.,Johnson, L.N.
      (1997) Structure 5: 1413
    • Effects of Commonly Used Cryoprotectants on Glycogen Phosphorylase Activity and Structure
      Tsitsanou, K.E.,Oikonomakos, N.G.,Zographos, S.E.,Skamnaki, V.T.,Gregoriou, M.,Watson, K.A.,Johnson, L.N.,Fleet, G.W.J.
      () TO BE PUBLISHED --: --


    Organizational Affiliation

    Institute of Biological Research and Biotechnology, The National Hellenic Research, Athens, Greece. nikos@aegean.eie.gr




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
PROTEIN (GLYCOGEN PHOSPHORYLASE)
A
842Oryctolagus cuniculusMutation(s): 0 
Gene Names: PYGM
EC: 2.4.1.1
Find proteins for P00489 (Oryctolagus cuniculus)
Go to Gene View: PYGM
Go to UniProtKB:  P00489
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download SDF File 
Download CCD File 
A
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
GLC
Query on GLC

Download SDF File 
Download CCD File 
A
ALPHA-D-GLUCOSE
C6 H12 O6
WQZGKKKJIJFFOK-DVKNGEFBSA-N
 Ligand Interaction
BIN
Query on BIN

Download SDF File 
Download CCD File 
A
2,3-DICARBOXY-4-(2-CHLORO-PHENYL)-1-ETHYL-5-ISOPROPOXYCARBONYL-6-METHYL-PYRIDINIUM
C20 H21 Cl N O6
HMSIYRVIPQHZBI-UHFFFAOYSA-O
 Ligand Interaction
PLP
Query on PLP

Download SDF File 
Download CCD File 
A
PYRIDOXAL-5'-PHOSPHATE
VITAMIN B6 Phosphate
C8 H10 N O6 P
NGVDGCNFYWLIFO-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
SEP
Query on SEP
A
L-PEPTIDE LINKINGC3 H8 N O6 PSER
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
BINKi: 10.8 nM BINDINGMOAD
BINKi: 10.8 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.189 
  • Space Group: P 43 21 2
Unit Cell:
Length (Å)Angle (°)
a = 127.200α = 90.00
b = 127.200β = 90.00
c = 115.800γ = 90.00
Software Package:
Software NamePurpose
X-PLORrefinement
DENZOdata reduction
SCALEPACKdata scaling
X-PLORphasing
X-PLORmodel building

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1999-02-26
    Type: Initial release
  • Version 1.1: 2008-04-26
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance