The human ABH2 protein, an α-Ketoglutarate/Fe(II)-dependent dioxygenase, repairs alkylation damage in DNA through oxidative demethylation, with relative specificity for 1-methyladenine (m1A) and 3-methylcytosine (m3C) lesions. In addition to understanding how these systems correct certain DNA defects, it is important to thoroughly analyze the factors that influence the functioning of these catalytic protein complexes and the conditions that allow these systems to function optimally. While several studies have already independently examined the factors associated with ABH2 enzyme functioning, a comprehensive analysis of these determinants has yet to be conducted.<br/><br/>In this project we examined the factors that regulate ABH2 function. Here we have evaluated the effects that varying concentrations of α-ketoglutarate, iron (II), and ascorbic acid have on the ability of ABH2 to correct m1A and m3C lesions in DNA. Additionally, we have reported the impact of pH and temperature on the catalytic repair of m1A and m3C lesions by ABH2. We also investigated whether various reducing agents could be used in place of ascorbic acid in the oxidative demethylation reaction catalyzed by ABH2. The results indicate that the optimal operating conditions for ABH2 may differ from what has been previously reported in the literature. Furthermore, our findings indicate that m3C and m1A lesions are repaired more efficiently by ABH2 at pH conditions below the pKa values for these lesions.

Comprehensive kinetic study of ALKBH2 and related family enzymes

254th National Meeting (2017)

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