The reaction of glyoxal with nucleic acid components: V. Denaturation of DNA under the action of glyoxal☆

Abstract 1. In the reaction of glyoxal with native DNA of T2 phage at temperatures below its T m modified deoxyguanosine residues are formed. 2. Kinetics of the unwinding of T2 phage DNA suggest that the reaction of glyoxal with native DNA results in fixation of the transiently-open regions of the bihelical structure and in further propagation of the defective regions leading to complete denaturation. 3. In contrast to the action of formaldehyde the action of glyoxal leads primarily to the unwinding of G · C-rich regions of DNA.