Abundant graft chains do not influence coil-to-helix but α-to-β transition of polylysine backbone, resulting in thermoreversible β-to-α transition

摘要: We have demonstrated that cationic comb-type copolymers (PLL-g-Dex) consisting of a polylysine backbone and abundant grafts water-soluble polymers stabilize DNA hybrids. Furthermore, the were found to accelerate strand exchange reaction between double-stranded its complementary single-stranded DNA. In this study, we investigated pH-induced coil-to-helix temperature-induced α-to-β transition PLL-g-Dex evaluate effect graft chains on conformation backbone. The was hardly influenced by grafted dextran. copolymer having 24 mol% (93 wt%) dextran still underwent transition. No change in pH with grafting density observed. contrast transition, impacted even at 1 (38 affected PLL temperature increased from 45°C 77 °C 11 (88 grafting, resulted stabilization helical structure higher temperature. thermoreversible β-to-α observed for particular degree. seemingly modified inter-strands or inter-segments interactions backbones which are required β-sheet assembling.