Psoralen C2 at the 5’-terminus of an oligonucleotide serves effectively as a cross-linking reagent in double-stranded oligonucleotides. The 6 atom spacer arm of Psoralen C6 allows cross-linking with a triplex oligonucleotide strand. Click Chemistry with psoralen azide and one of our many nucleosidic and non-nucleosidic alkyne derivatives has the potential to generate a variety of practical cross-linkers. The well known reversible cross-linking behavior of psoralen with an adjacent thymidine residue could be very useful.
Coupling: 10 minute coupling time recommended.
Deprotection: Mild: 0.4M Methanolic NaOH 17hr @ RT or ammonium hydroxide 24h @ RT.|Note: NaOH is not compatible with dmf protecting groups.
Psoralen C2 is designed to crosslink to a T residue adjacent to the 3'-terminus of the opposite strand of double stranded DNA. Psoralen C6 is intended to fulfill the same purpose but, with the longer spacer, crosslinks to the triple strand of triplex DNA.Max excitation=330nm, observed at max 395nm||
Psoralens are a class of naturally occurring heterocyclic compounds which intercalates between bases in double-stranded or triple stranded DNA. Upon exposure to long wavelength light (350 nm) Psoralen forms covalent linkages to Thymidine (cyclobutane linkage). Psoralen is a bifunctional reagent and can form either a monoadduct, linking one adjacent thymidine on the same or complimentary strand, or a diadduct, linking adjacent thymidines on the same or complimentary strands. Diadducts formed between adjacent thymidines are photoreversable with short wavelength UV light (254 nm).