2000 Volume 40 Issue 4 Pages 244-248
We have designed comb-type copolymer with polycation backbone (polylysine) grafted with hydrophilic side chains as a stabilizer for triple helical DNA. The copolymer considerably increased the thermal stability of triplex structure but did not affect the reversible transition between triplex and single-stranded DNA. An in vitro electrophoretic mobility shift assay revealed that the copolymer remarkably diminishes potassium inhibition of the purine motif triplex formation up to 200mM as well as the pH-dependence of the pyrimidine motif. Moreover the triplex-stabilizing efficiency of the copolymer was significantly higher than that of other oligocations like spermine and spermidine. Not only being good DNA triplex stabilizer, it has also been shown to accelerate DNA strand exchange reactions. From these, we conclude that this copolymer is capable of either “stabilizing” or “activating” DNA hybrids.
