TY - JOUR
T1 - Activation of DNA strand exchange by cationic comb-type copolymers
T2 - Effect of cationic moieties of the copolymers
AU - Choi, Sung Won
AU - Kano, Arihiro
AU - Maruyama, Atsushi
N1 - Funding Information:
We thank FASMAC for oligonucleotide syntheses. We would like to gratefully acknowledge the Grant-in-Aid for Scientific Research (No. 16200034) from the Japan Society for the Promotion of Science (JSPS), the Joint Project for Materials Chemistry, and the G-COE Program from the Ministry of Education, Culture, Science, Sports and Technology of Japan, and A3 Foresight Program from JSPS, National Natural Science Foundation of China (NSFC), and Korea Science and Engineering Foundation (KOSEF). S.W.C. was supported by the JSPS postdoctoral fellowship. Funding to pay the Open Access publication charges for this article was provided by Japan Science and Technology Agency.
PY - 2008/1
Y1 - 2008/1
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=38349159242&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=38349159242&partnerID=8YFLogxK
U2 - 10.1093/nar/gkm1035
DO - 10.1093/nar/gkm1035
M3 - Article
C2 - 18033803
AN - SCOPUS:38349159242
VL - 36
SP - 342
EP - 351
JO - Nucleic Acids Research
JF - Nucleic Acids Research
SN - 0305-1048
IS - 1
ER -