Electrochemical Genotoxicity Screening for Arylamines Bioactivated by N-Acetyltransferase

Abstract

Genotoxicity screening sensors that measure DNA damage from metabolism of arylamines were developed and evaluated. The sensors feature ultrathin films containing DNA and N-acetyltransferase (NAT) on pyrolytic graphite (PG) electrodes. NAT in the film catalyzed the conversion of the arylamine 2-aminofluorene (2-AF) to 2-acetylaminofluorene (2-AAF) by acetyl coenzyme A (AcCoA) dependent N-acetylation, as verified by liquid chromatography. DNA damage in the films from exposure to reactive 2-AF metabolites was measured subsequent to the enzyme reaction using catalytic voltammetric oxidation with Ru(bpy)32+. Square wave voltammetric (SWV) peaks increased with enzyme reaction time, and relative DNA damage rates at pH 5.8 were measured within 2 min. Control incubations of DNA/NAT films without AcCoA gave no significant sensor response. CapLC-MS/MS analysis of 2-AAF/DNA reaction products was consistent with 2-AF-guanine adducts formed in the films. DNA damage occurred more rapidly under weakly acidic conditions (pH 5.5-5.8) than at neutral pH, suggesting that genotoxicity from arylamine metabolism by NAT could be more significant in slightly acidic environments.

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Electrochemical detection of in situ DNA damage induced by enzyme-catalyzed Fenton reaction. Part II in hydrophobic room temperature ionic liquid

“…Therefore, the detection of DNA damage, which is tightly related to mutagenesis, carcinogenesis, aging and neurodegenerative diseases, has become one of the most important DNA research fields [1][2][3]. While various analytical techniques have been employed to detect DNA damage, electrochemical methods have attracted significant attention mainly because of their simplicity, fast response, relatively cheap cost and low power requirement [4][5][6][7][8][9].…”