Novel diazirine-containing DNA photoaffinity probes for the investigation of DNA-protein-interactions.

An investigation of the precise interactions between damaged DNA and DNA repair enzymes is required in order to understand the lesion recognition step, which is one of the most fundamental processes in DNA repair. Most recently, photoaffinity labeling approaches have enabled the analysis of even transient protein-DNA interactions. Here we report the synthesis and evaluation of oligonucleotides that contain two photoaffinity "catcher moieties" next to incorporated DNA lesions. With these DNA constructs it is possible to analyze the interactions between DNA lesions and the appropriate repair enzymes. The probes labeled the repair protein efficiently enough to enable subsequent protein analysis by mass spectrometry.