Discovery of Helicobacter pylori shikimate kinase inhibitors: bioassay and molecular modeling

Bioorg Med Chem. 2007 Jan 15;15(2):656-62. doi: 10.1016/j.bmc.2006.10.058. Epub 2006 Nov 1.

Abstract

Shikimate kinase (SK) is the fifth enzyme in the shikimate pathway and catalyzes the phosphate transfer from ATP to shikimate in generating shikimate 3-phosphate and ADP. SK has been developed as a promising target for the discovery of antibacterial agents. In this report, two small molecular inhibitors (compound 1, 3-methoxy-4-{[2-({2-methoxy-4-[(4-oxo-2-thioxo-1,3-thiazolidin-5-ylidene)methyl]phenoxy}methyl)benzyl]oxy}benzaldehyde; compound 2, 5-bromo-2-(5-{[1-(3,4-dichlorophenyl)-3,5-dioxo-4-pyrazolidinylidene]methyl}-2-furyl)benzoic acid) against Helicobacter pylori SK (HpSK) were successfully identified with IC(50) values of 5.5+/-1.2 and 6.4+/-0.4 microM, respectively. The inhibition kinetics shows that compound 1 is a noncompetitive inhibitor with respect to both shikimate and MgATP, and compound 2 is a competitive inhibitor toward shikimate and noncompetitive inhibitor with respect to MgATP. The surface plasmon resonance (SPR) technology based analysis reveals that the equilibrium dissociation constants (K(D)s) of compounds 1 and 2 with HpSK enzyme are 4.39 and 3.74 microM, respectively. The molecular modeling and docking of two inhibitors with HpSK reveals that the active site of HpSK is rather roomy and deep, forming an L-shape channel on the surface of the protein, and compound 1 prefers the corner area of L-shape channel, while compound 2 binds the short arm of the channel of SK in the binding interactions. It is expected that our current work might supply useful information for the development of novel SK inhibitors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Biological Assay
  • Cloning, Molecular
  • Drug Evaluation, Preclinical
  • Enzyme Inhibitors / chemical synthesis*
  • Enzyme Inhibitors / pharmacology*
  • Helicobacter pylori / drug effects
  • Helicobacter pylori / enzymology*
  • Helicobacter pylori / metabolism
  • Kinetics
  • Models, Molecular
  • Molecular Conformation
  • Phosphotransferases (Alcohol Group Acceptor) / antagonists & inhibitors*
  • Phosphotransferases (Alcohol Group Acceptor) / biosynthesis
  • Phosphotransferases (Alcohol Group Acceptor) / chemistry
  • Recombinant Proteins / biosynthesis
  • Surface Plasmon Resonance

Substances

  • Enzyme Inhibitors
  • Recombinant Proteins
  • Phosphotransferases (Alcohol Group Acceptor)
  • shikimate kinase