Biologically relevant oxidants cause bound proteins to readily oxidatively cross-link at Guanine.

ABSTRACT: Oxidative DNA-protein cross-links have received less attention than other types of DNA damage and remain as one of the least understood types of oxidative lesion. A model system using ribonuclease A and a 27-nucleotide DNA was used to determine the propensity of oxidative cross-linking to occur in the presence of oxidants. Cross-link formation was examined using four different oxidation systems that generate singlet oxygen, superoxide, and metal-based Fenton reactions. It is shown that oxidative cross-linking occurs in yields ranging from 14% to a maximal yield of 61% in all oxidative systems when equivalent concentrations of DNA and protein are present. Because singlet oxygen is the most efficient oxidation system in generating DNA-protein cross-links, it was chosen for further analyses.

SUBMITTER: Solivio MJ 

PROVIDER: S-EPMC5507331 | biostudies-literature | 2012 Feb

REPOSITORIES: biostudies-literature