Inhibition and biochemical characterization of methicillin-resistant Staphylococcus aureus shikimate dehydrogenase: an in silico and kinetic study

Molecules. 2014 Apr 10;19(4):4491-509. doi: 10.3390/molecules19044491.

Abstract

Methicillin-resistant Staphylococcus auerus (MRSA) strains are having a major impact worldwide, and due to their resistance to all β-lactams, an urgent need for new drugs is emerging. In this regard, the shikimate pathway is considered to be one of the metabolic features of bacteria and is absent in humans. Therefore enzymes involved in this route, such as shikimate dehydrogenase (SDH), are considered excellent targets for discovery of novel antibacterial drugs. In this study, the SDH from MRSA (SaSDH) was characterized. The results showed that the enzyme is a monomer with a molecular weight of 29 kDa, an optimum temperature of 65 °C, and a maximal pH range of 9-11 for its activity. Kinetic studies revealed that SDH showed Michaelis-Menten kinetics toward both substrates (shikimate and NADP+). Initial velocity analysis suggested that SaSDH catalysis followed a sequential random mechanism. Additionally, a tridimensional model of SaSDH was obtained by homology modeling and validated. Through virtual screening three inhibitors of SaSDH were found (compounds 238, 766 and 894) and their inhibition constants and mechanism were obtained. Flexible docking studies revealed that these molecules make interactions with catalytic residues. The data of this study could serve as starting point in the search of new chemotherapeutic agents against MRSA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcohol Oxidoreductases / antagonists & inhibitors*
  • Alcohol Oxidoreductases / chemistry
  • Alcohol Oxidoreductases / genetics
  • Alcohol Oxidoreductases / metabolism
  • Anti-Bacterial Agents
  • Drug Discovery
  • Enzyme Inhibitors / chemistry*
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Gene Expression
  • High-Throughput Screening Assays
  • Kinetics
  • Methicillin-Resistant Staphylococcus aureus / chemistry*
  • Methicillin-Resistant Staphylococcus aureus / enzymology
  • Molecular Docking Simulation
  • Molecular Dynamics Simulation
  • Molecular Weight
  • NADP / chemistry*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Shikimic Acid / chemistry*
  • Structural Homology, Protein
  • Substrate Specificity
  • User-Computer Interface
  • beta-Lactam Resistance
  • beta-Lactams

Substances

  • Anti-Bacterial Agents
  • Enzyme Inhibitors
  • Recombinant Proteins
  • beta-Lactams
  • Shikimic Acid
  • NADP
  • Alcohol Oxidoreductases
  • Shikimate dehydrogenase