Quantitation of O6-methylguanine-DNA methyltransferase in HeLa cells Academic Article uri icon


MeSH Major

  • Gastric Mucosa
  • Gastrointestinal Diseases
  • Intestinal Mucosa
  • Oxidative Stress
  • Reactive Oxygen Species


  • A synthetic DNA polymer containing [8-3H]O6-methylguanine (m6G) was used as a substrate to assay the in situ demethylation of the alkylated base by an activity in HeLa cell extracts. The repair activity appears to be similar to the O6-methylguanine-DNA methyltransferase of E. coli and to be inactivated by reaction with the substrate. Extracts of a methylation-repair proficient (Mer+) cell strain, HeLa CCL2, were found to contain m6G repair activity equivalent to approx. 100 000 molecules of methyltransferase per cell, assuming that each molecule can demethylate one m6G residue. No activity could be detected in the extract of a repair deficient (Mer-) cell strain, HeLa S3, and there is no evidence of an inhibitor of repair activity in this strain.

publication date

  • January 1983



  • Academic Article


Digital Object Identifier (DOI)

  • 10.1016/0165-7992(83)90164-1

Additional Document Info

start page

  • 221

end page

  • 8


  • 119


  • 3-4