Effect of linker length on photo-cross-linking position mediated by click chemistryvia[2+2]photocycloaddition

Ultrafast reversible DNA/RNA photo-cross-linking is a powerful tool for regulating the target strand in living cells. In particular, 3-cyanovinylcarbazole (K-CNV) and 3-cyanovinylcarbazole modified byd-threoninol (D-CNV) can photo-cross-link to pyrimidine bases within a few seconds of photoirradiation. However, these photo-cross-linkers can only cross-link to the counter base if it is adjacent to the 5 '-side (-1 position). In this study, we synthesized novel photo-cross-linkers with varying linker lengths capable of photo-cross-linking with pyrimidine bases at locations other than the -1 positionviaclick chemistry. The photo-cross-linking site was dependent on linker length.