Activation of DNA strand exchange by cationic comb-type copolymers: Effect of cationic moieties of the copolymers

Sung Won Choi, Arihiro Kano, Atsushi Maruyama

Research output: Contribution to journalArticlepeer-review

34 Citations (Scopus)


We have previously reported that poly(L-lysine)-graft-dextran cationic comb-type copolymers accelerate strand exchange reaction between duplex DNA and its complementary single strand by > 4 orders of magnitude, while stabilizing duplex. However, the stabilization of the duplex is considered principally unfavourable for the accelerating activity since the strand exchange reaction requires, at least, partial melting of the initial duplex. Here we report the effects of different cationic moieties of cationic comb-type copolymers on the accelerating activity. The copolymer having guanidino groups exhibited markedly higher accelerating effect on strand exchange reactions than that having primary amino groups. The high accelerating effect of the former is considered to be due to its lower stabilizing effect on duplex DNA, resulting from its increased affinity to single-stranded DNA. The difference in affinity was clearly demonstrated by a fluorescence correlation spectroscopy study; the interaction of the former with single-stranded DNA still remained high even at 1 M NaCl, while that of the latter completely disappeared. These results suggest that some modes of interactions, such as hydrogen bonding, other than electrostatic interactions between the copolymers having guanidino groups and DNAs may be involved in strand exchange activation.

Original languageEnglish
Pages (from-to)342-351
Number of pages10
JournalNucleic acids research
Issue number1
Publication statusPublished - Jan 2008

All Science Journal Classification (ASJC) codes

  • Genetics


Dive into the research topics of 'Activation of DNA strand exchange by cationic comb-type copolymers: Effect of cationic moieties of the copolymers'. Together they form a unique fingerprint.

Cite this