Electrochemistry of the [4Fe4S] Cluster in Base Excision Repair Proteins: Tuning the Redox Potential with DNA.

ABSTRACT: Escherichia coli endonuclease III (EndoIII) and MutY are DNA glycosylases that contain [4Fe4S] clusters and that serve to maintain the integrity of the genome after oxidative stress. Electrochemical studies on highly oriented pyrolytic graphite (HOPG) revealed that DNA binding by EndoIII leads to a large negative shift in the midpoint potential of the cluster, consistent with stabilization of the oxidized [4Fe4S]³⁺ form. However, the smooth, hydrophobic HOPG surface is nonideal for working with proteins in the absence of DNA. In this work, we use thin film voltammetry on a pyrolytic graphite edge electrode to overcome these limitations. Improved adsorption leads to substantial signals for both EndoIII and MutY in the absence of DNA, and a large negative potential shift is retain

SUBMITTER: Bartels PL 

PROVIDER: S-EPMC5423460 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature