Evidence for two DNA repair enzymes for 8-hydroxyguanine (7,8-dihydro-8-oxoguanine) in human cells.
Year: 1993
Type: article
Abstract: Two DNA repair enzymes for 8-hydroxyguanine (also known as 7,8-dihydro-8-oxoguanine; OH8Gua, oxo8Gua) have been identified in human HeLa cell nuclear extract. One is OH8Gua-glycosylase and the other is OH8Gua-endonuclease that lacks OH8Gua-glycosylase activity. They were separated by heparin-Sepharose column chromatography and characterized by endonuclease nicking assay or by measuring the OH8Gua released from substrate DNA using high pressure liquid chromatography-electrochemical detection. Both OH8Gua repair enzymes act only on the OH8Gua-containing strand of the duplex substrate DNA containing OH8Gua/C, OH8Gua/T, or OH8Gua/G. DNA containing OH8Gua/A base pair was very poor substrate for either enzymes. OH8Gua-endonuclease simultaneously cleaves phosphodiester bonds on both sides of the OH8Gua residue, leaving 5'-hydroxy and 3'-hydroxy groups.
Source: Journal of Biological Chemistry
Authors: T Bessho, K Tano, H Kasai, E Ohtsuka, S Nishimura
Institution: Merck & Co., Inc., Rahway, NJ, USA (United States)
Language: English
Topic: DNA Repair Mechanisms
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,430
OpenAlex ID: W1518449135