Conformational Changes of DNA by Photoirradiation of DNA-Bis(Zn^II-Cyclen)-Azobenzene Complex

Abstract

Bis(Zn(II)-cyclen)-azobenzene derivative, which has two Zn(II)-macrocyclic tetraamine complexes connected through azobenzene spacer, has been synthesized as a cross-linking agent fordoublestranded DNA in aqueous solution. The Zn(II)-cyclen derivative selectively binds to A-T base pairs producing complexes between the Zn(II)-cyclen moiety and the imide-deprotonated thymine with breaking A-T base pairs. The azobenzene spacer undergoes cis/trans photoisomerization in the complex between the Zn(II)-cyclen derivative and the DNA duplex. The conformation of the DNA remarkably changed by photoisomerization of the azobenzene linker, when the Zn(II)-cyclen derivative binds to the DNA duplex with an interstrand cross-linking manner

Azobenzene-Bridged Expanded “Texas-sized” Box: A Dual-Responsive Receptor for Aryl Dianion Encapsulation

“…The synthesis of AzoTxSB is summarized in Scheme . The key trimeric fragment, 2,6-di­(1H-imidazol-1-yl) pyridine, and 1,4-bis-bromomethylazobenzene were prepared according to previous reports. , Cyclization then gave the corresponding macrocycle in the form of its tetrabromide salt. Exposure to aqueous NH 4 PF 6 gave the corresponding tetrahexafluorophosphate salt, AzoTxSB , in 22% yield (based on cyclization and salt exchange).…”

Towards a light driven molecular assembler

“…The ditopic receptor was prepared in a three-step synthesis (for details see Supplementary Fig. 1) 16 .…”

DNA Length Dependent Photocurrent of Diketopyrrolopyrrole Aggregates Constructed with DNA

“…It has been well known that Zn II -cyclen complex selectively and strongly binds to thymine base disrupting a A-T base pair in double stranded DNA via the coordination of Zn II ion with the deprotonated imide nitrogen of thymine, and the hydrogen bonds between the carbonyl groups of thymine and the NH groups of cyclen. 4 This characteristic recognition of Zn II -cyclen has been applied to probes for DNA assays, 5 a cross linker, 6 a cleavage regent, 7 and a supramolecule. 8 Thus, we can utilize Zn II -cyclen as the receptor unit of chromophore building blocks.…”