Inhibition of mushroom tyrosinase by a newly synthesized ligand: inhibition kinetics and computational simulations

J Biomol Struct Dyn. 2012;30(4):448-59. doi: 10.1080/07391102.2012.682210. Epub 2012 Jun 11.

Abstract

Alterations in the synthesis of melanin contribute to a number of diseases; therefore, the design of new tyrosinase inhibitors is very important. Mushroom tyrosinase (MT) is a metalloenzyme, which plays an important role in melanin biosynthesis. In this study, the inhibitory effect of a novel designed compound, i.e. 2-((1Z)-(2-(2,4-dinitrophenyl)hydrazin-1-ylidene)methyl)phenol, as a specific ligand which can bind to the copper ion of MT, has been assessed. The ligand was found to competitively inhibit both the cresolase and catecholase activities of MT, with small inhibition constants of 2.8 and 2.6 μM, respectively. Intrinsic fluorescence studies were performed to gain more information on the binding constants. Docking results indicated that the ligand binds to copper ions in the active site of MT via the OH group of the ligand. The ligand makes four hydrogen bonds with aspartic acid and one hydrogen bond with the histidine residue in the active site. Molecular dynamics results show that ligand binds to the MT via both electrostatic and hydrophobic interactions with its different parts.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agaricales / chemistry
  • Agaricales / enzymology
  • Aspartic Acid / chemistry
  • Catalytic Domain
  • Catechol Oxidase / antagonists & inhibitors
  • Catechol Oxidase / chemistry*
  • Catechol Oxidase / metabolism
  • Copper / chemistry*
  • Enzyme Inhibitors / chemical synthesis*
  • Histidine / chemistry
  • Hydrazones / chemical synthesis*
  • Hydrogen Bonding
  • Hydrophobic and Hydrophilic Interactions
  • Kinetics
  • Ligands
  • Molecular Dynamics Simulation
  • Monophenol Monooxygenase / antagonists & inhibitors
  • Monophenol Monooxygenase / chemistry*
  • Monophenol Monooxygenase / metabolism
  • Nitrobenzenes / chemical synthesis*
  • Protein Binding
  • Spectrometry, Fluorescence

Substances

  • 2-((2-(2,4-dinitrophenyl)hydrazin-1-ylidene)methyl)phenol
  • Enzyme Inhibitors
  • Hydrazones
  • Ligands
  • Nitrobenzenes
  • Aspartic Acid
  • Histidine
  • Copper
  • Catechol Oxidase
  • Monophenol Monooxygenase