Poly (L-lysine)-graft-dextran acts as a nucleic acid chaperone for tetramolecular quadruplex formation

DNA sequence 5'-TGGGGT-3'; TG(4)T takes an intermolecular quadruplex structure which composed of four TG(4)T strands associated together by four layers of G-quartets with parallel strand orientation. Interestingly, its association rate is considerably slow, hampering its application of DNA nanobiotechnology. We have reported that the cationic comb-type copolymer seemingly promoted the nucleation step of DNA hybridization to accelerate duplex and triplex formation. Then, we presumed that the copolymer also influenced kinetics of the quadruplex formation. In this study, the effect of the copolymer on the intermolecular quadruplex folding was investigated. The copolymer was found to accelerate both the association and dissociation of tetramolecular quadruplex. We concluded that PLL-g-Dex acts as a nucleic acid chaperone for tetramolecular quadruplex formation.