Catalytic and inhibitor binding properties of zebrafish monoamine oxidase (zMAO): comparisons with human MAO A and MAO B

Comp Biochem Physiol B Biochem Mol Biol. 2011 Jun;159(2):78-83. doi: 10.1016/j.cbpb.2011.02.002. Epub 2011 Feb 23.


A comparative investigation of substrate specificity and inhibitor binding properties of recombinant zebrafish (Danio rerio) monoamine oxidase (zMAO) with those of recombinant human monoamine oxidases A and B (hMAO A and hMAO B) is presented. zMAO oxidizes the neurotransmitter amines (serotonin, dopamine and tyramine) with k(cat) values that exceed those of hMAO A or of hMAO B. The enzyme is competitively inhibited by hMAO A selective reversible inhibitors with the exception of d-amphetamine where uncompetitive inhibition is exhibited. The enzyme is unreactive with most MAO B-specific reversible inhibitors with the exception of chlorostyrylcaffeine. zMAO catalyzes the oxidation of para-substituted benzylamine analogs exhibiting (D)k(cat) and (D)(k(cat)/K(m)) values ranging from 2 to 8. Structure-activity correlations show a dependence of log k(cat) with the electronic factor σ(p) with a ρ value of +1.55±0.34; a value close to that for hMAO A but not with MAO B. zMAO differs from hMAO A or hMAO B in benzylamine analog binding correlations where an electronic effect (ρ=+1.29±0.31) is observed. These data demonstrate zMAO exhibits functional properties similar to hMAO A as well as exhibits its own unique behavior. These results should be useful for studies of MAO function in zebrafish models of human disease states.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Benzylamines / metabolism
  • Binding Sites
  • Biocatalysis / drug effects
  • Dextroamphetamine / chemistry
  • Dextroamphetamine / pharmacology
  • Dopamine / metabolism
  • Gene Expression
  • Humans
  • Isoenzymes / genetics
  • Isoenzymes / metabolism*
  • Kinetics
  • Monoamine Oxidase / genetics
  • Monoamine Oxidase / metabolism*
  • Monoamine Oxidase Inhibitors / chemistry
  • Monoamine Oxidase Inhibitors / pharmacology
  • Oxidation-Reduction
  • Pichia
  • Protein Binding
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism*
  • Serotonin / metabolism
  • Species Specificity
  • Substrate Specificity
  • Tyramine / metabolism
  • Zebrafish / genetics
  • Zebrafish / metabolism*


  • Benzylamines
  • Isoenzymes
  • Monoamine Oxidase Inhibitors
  • Recombinant Proteins
  • Serotonin
  • Monoamine Oxidase
  • Dextroamphetamine
  • Dopamine
  • Tyramine