DNA photo-cross-linking using a pyranocarbazole-modified oligodeoxynucleotide with a -threoninol linker

An alternative photo-cross-linker having a d -threoninol skeleton instead of the 2′-deoxyribose backbone in 3-cyanovinylcarbazole ( CNV K) was investigated to improve the photoreactivity of photo-cross-linkers; the photo-cross-linking rate of 3-cyanovinylcarbazole with d -threoninol ( CNV D) was found to be greater than that of CNV K. Therefore, in this study, a novel photo-cross-linker having pyranocarbazole ( PC X) and d -threoninol instead of the 2′-deoxyribose backbone in PC X ( PCX D) was developed. The PCX D in double-stranded DNA photo-cross-linked to a pyrimidine base at the −1 position of a complementary strand similar to PC X. Furthermore, the photoreactivity of PCX D was significantly higher than that of PC X. The introduction of d -threoninol improved the reactivity of pyranocarbazole to cytosine, the use of PCX D may extend the applicability of the photo-cross-linking reaction for DNA manipulation. In particular, this novel photo-cross-linker can contribute to the photochemical regulation of gene expression or biological events in a living cell. An alternative more efficient photo-cross-linker having a d -threoninol skeleton instead of the 2′-deoxyribose backbone in pyranocarbazole was investigated to improve the photoreactivity of photo-cross-linkers.