Electron transfer and guanine photodamage in DNA condensate

Abstract

In in vivo environments, DNA coexists with enormous biomolecules. A high concentration of biomolecules definitely changes both the environment around DNA and DNA conformations. The behavior of DNA-mediated electron transfer (ET) in vivo is expected to be different from that in dilute aqueous solution, but no studies have thus far been conducted on DNA-mediated ET in a crowded molecular medium. We reported that the efficiency of guanine decomposition induced by DNA-mediated ET under crowded environments formed by various cosolutes obviously differed from the efficiency in dilute aqueous solution. DNA is also often packed into a condensed phase under crowded environment. We investigated the efficiency of guanine oxidation in DNA condenses using pyrene-modified oligonucleotides. The results showed that guanine decomposition via photoinduced electron transfer in DNA condensate was dramatically promoted.