Modulation of pantothenate kinase 3 activity by small molecules that interact with the substrate/allosteric regulatory domain

Chem Biol. 2010 Aug 27;17(8):892-902. doi: 10.1016/j.chembiol.2010.06.006.

Abstract

Pantothenate kinase (PanK) catalyzes the rate-controlling step in coenzyme A (CoA) biosynthesis. PanK3 is stringently regulated by acetyl-CoA and uses an ordered kinetic mechanism with ATP as the leading substrate. Biochemical analysis of site-directed mutants indicates that pantothenate binds in a tunnel adjacent to the active site that is occupied by the pantothenate moiety of the acetyl-CoA regulator in the PanK3acetyl-CoA binary complex. A high-throughput screen for PanK3 inhibitors and activators was applied to a bioactive compound library. Thiazolidinediones, sulfonylureas and steroids were inhibitors, and fatty acyl-amides and tamoxifen were activators. The PanK3 activators and inhibitors either stimulated or repressed CoA biosynthesis in HepG2/C3A cells. The flexible allosteric acetyl-CoA regulatory domain of PanK3 also binds the substrates, pantothenate and pantetheine, and small molecule inhibitors and activators to modulate PanK3 activity.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetyl Coenzyme A / metabolism
  • Allosteric Regulation / drug effects
  • Binding Sites
  • Coenzyme A / biosynthesis
  • Enzyme Activation / drug effects
  • Enzyme Inhibitors / chemistry
  • Enzyme Inhibitors / metabolism
  • Enzyme Inhibitors / pharmacology
  • Hep G2 Cells
  • High-Throughput Screening Assays
  • Humans
  • Isoenzymes / antagonists & inhibitors
  • Isoenzymes / chemistry
  • Isoenzymes / genetics
  • Isoenzymes / metabolism
  • Models, Molecular
  • Mutagenesis, Site-Directed
  • Phosphotransferases (Alcohol Group Acceptor) / antagonists & inhibitors
  • Phosphotransferases (Alcohol Group Acceptor) / chemistry*
  • Phosphotransferases (Alcohol Group Acceptor) / genetics
  • Phosphotransferases (Alcohol Group Acceptor) / metabolism*
  • Protein Binding
  • Protein Structure, Tertiary
  • Small Molecule Libraries / chemistry
  • Small Molecule Libraries / metabolism*
  • Small Molecule Libraries / pharmacology
  • Substrate Specificity
  • Sulfonylurea Compounds / metabolism
  • Thiazolidinediones / metabolism

Substances

  • Enzyme Inhibitors
  • Isoenzymes
  • Small Molecule Libraries
  • Sulfonylurea Compounds
  • Thiazolidinediones
  • Acetyl Coenzyme A
  • 2,4-thiazolidinedione
  • Phosphotransferases (Alcohol Group Acceptor)
  • pantothenate kinase
  • Coenzyme A

Associated data

  • PDB/3MK6