Point Mutation Selective Photo-Cross-Linking Reactions by Diazirine-Derivatized ODNs

Point mutations and single base mutations are the dominant mutations found in the KRAS gene. Systematic knockout of the KRAS gene with these point mutations is still challenging. In this study, we developed novel photo-cross-linking oligonucleotides (^<b>p</b><b>U</b>_<b>1</b><b>–ODN</b> and ^<b>p</b><b>U</b>_<b>2</b><b>–ODN</b>) that had a diazirine group at the 5-position of the uridine derivatives. Photo-cross-linking studies of the oligonucleotides with wild-type and mutated RNAs revealed that ^<b>p</b><b>U</b>_<b>2</b><b>–ODN</b> efficiently and selectively reacts with the mutated RNAs that contain a cytidine, guanosine, or uridine residue at the frontal position of the ^<b>p</b><b>U</b>_<b>2</b> nucleoside. These results suggest that ^<b>p</b><b>U</b>_<b>2</b><b>–ODN</b> is a promising candidate for use as a photo-cross-linking ODN to selectively inhibit the activity of mRNAs with a point mutation.