Aryl N-methyltransferase: Ring methylation of tryptamine

  • Ellen Sue Lyon
  • William B Jakoby


A wide range of amines is known to be methylated in reactions catalyzed by mammalian enzymes with S-methyl-L-adenosine as the methyl donor. The observation of a system of low substrate specificity in extracts of rabbit lung by Axelrod and its reported distribution (Axelrod, J., 1962, Saavedra, J.M., et. al., 1973, Borchardt, R.T., 1980), suggested the presence of enzymes active in detoxication processes and prompted our investigation. This report concerns an enzyme from rabbit liver, arylamine N-methyltransferase, that is active with arylamines and with tryptamine, but not phenethylamine, and that has been purified to homogeneity. A natural inhibitor of the enzyme, also observed in rabbit lung (Axelrod, J., 1962), has now been isolated although it is only partially characterized.


Methyl Donor Standard Assay Condition Rabbit Liver Rabbit Lung Methyl Tryptophan 
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© The contributors 1982

Authors and Affiliations

  • Ellen Sue Lyon
  • William B Jakoby

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