Evidence for two closely related isozymes of arylamine N-acetyltransferase in human liver

FEBS Lett. 1989 Feb 13;244(1):203-7. doi: 10.1016/0014-5793(89)81193-7.


Acetyl CoA-dependent arylamine N-acetyltransferase (EC is the target of a genetic polymorphism in the metabolism of drugs and carcinogens. N-Acetyltransferase was purified 1000-fold from cytosol of human liver and its identity was verified by amino acid sequence homology of two of its tryptic peptides with published rabbit and chicken N-acetyltransferase sequences. Enzyme activity correlated with the presence of two proteins, NAT-1 and NAT-2, with indistinguishable molecular masses (31 kDa). NAT-1 and NAT-2 could be separated by anion-exchange chromatography and were functionally distinguished by their different apparent affinities for the acceptor amine sulfamethazine (SMZ). Antibodies raised against NAT-1 were able to recognize both isozymes on Western blots.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetyltransferases / isolation & purification*
  • Amino Acid Sequence
  • Animals
  • Arylamine N-Acetyltransferase / genetics
  • Arylamine N-Acetyltransferase / isolation & purification*
  • Arylamine N-Acetyltransferase / metabolism
  • Blotting, Western
  • Chickens
  • Chromatography, High Pressure Liquid
  • Chromatography, Ion Exchange
  • Electrophoresis, Polyacrylamide Gel
  • Humans
  • Isoenzymes / genetics
  • Isoenzymes / isolation & purification*
  • Isoenzymes / metabolism
  • Liver / enzymology*
  • Molecular Sequence Data
  • Molecular Weight
  • Peptide Fragments
  • Polymorphism, Genetic
  • Rabbits
  • Sequence Homology, Nucleic Acid
  • Substrate Specificity
  • Sulfamethazine / metabolism
  • Trypsin


  • Isoenzymes
  • Peptide Fragments
  • Sulfamethazine
  • Acetyltransferases
  • Arylamine N-Acetyltransferase
  • Trypsin