刊名:Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis
出版年:1997
出版时间:September, 1997
年:1997
卷:379
期:1
页码:S30
全文大小:121 K
文摘
The human AP endonuclease (APE) activity counteracts the mutagenic and cytotoxic effects of the frequent genomic lesions abasic (AP) sites. In order to investigate the interindividual variability of APE levels a simple and quantitative assay was developed. Crude lymphocyte extracts were incubated with a depurinated or a control supercoiled plasmid substrate and the accumulation of nicked circular plasmid forms was monitored by agarose gel electrophoresis. The detected incision activity was AP sites-dependent and EDTA-sensitive. The unit of enzymatic activity was defined as that able to incise one ng of plasmid DNA carrying one AP site/plasmid at 30° C in 10 min. The assay was used to measure the APE activity in ten healthy individuals of ages 25-48 years. Values ranged from 0.38 to 0.94 units/ng protein with a mean value of 0.62. This is the first estimate of the interindividual variability of this important DNA repair enzyme.