TY - JOUR
T1 - Amine induced Z-DNA in poly(dG-dC) · poly(dG-dC)
T2 - Circular dichroism and gel electrophoresis study
AU - Parkinson, A.
AU - Hawken, M.
AU - Hall, M.
AU - Sanders, K. J.
AU - Rodger, A.
PY - 2000/12/1
Y1 - 2000/12/1
N2 - Spermine and [Co(NH3)6]3+ are known to induce the B → Z transition in poly(dG-dC) · poly(dG-dC) DNA. In this paper gel electrophoresis shift assays using the long DNA poly(dG-dC) · poly(dG-dC) are developed to complement circular dichroism (CD) measurements of the conformation of the DNA in the presence of amines including spermine, spermidine, [Co(NH3)6]3+, (+)-[Co(en)3]3+ and (-)-[Co(en)3]3+ (en: ethylenediamine). CD is used to monitor the average conformation of the DNA and the gels show when there is a population of a given type of DNA in the solution. Spermidine is found to induce the transition at very low ionic strength, in contrast to literature wisdom. The cobalt amine-induced Z-DNA melts, with a broad transition, at a lower temperature than B-DNA. The electrophoresis data shows the presence of a DNA more flexible than B-DNA at low amine concentrations. This is ascribed to the existence of B/Z junctions. At higher amine concentrations, a DNA (Z-DNA) that is stiffer than B-DNA is observed. The Z-DNA induced by spermine is stiffer (runs more slowly on the gels) than that induced by the other amines. The spermine-DNA interaction is found to be very cooperative, whereas that of the cobalt amines is uncooperative. The kinetics of the B → Z transition with spermine at room temperature is very slow, whereas the cobalt amines induce it within seconds.
AB - Spermine and [Co(NH3)6]3+ are known to induce the B → Z transition in poly(dG-dC) · poly(dG-dC) DNA. In this paper gel electrophoresis shift assays using the long DNA poly(dG-dC) · poly(dG-dC) are developed to complement circular dichroism (CD) measurements of the conformation of the DNA in the presence of amines including spermine, spermidine, [Co(NH3)6]3+, (+)-[Co(en)3]3+ and (-)-[Co(en)3]3+ (en: ethylenediamine). CD is used to monitor the average conformation of the DNA and the gels show when there is a population of a given type of DNA in the solution. Spermidine is found to induce the transition at very low ionic strength, in contrast to literature wisdom. The cobalt amine-induced Z-DNA melts, with a broad transition, at a lower temperature than B-DNA. The electrophoresis data shows the presence of a DNA more flexible than B-DNA at low amine concentrations. This is ascribed to the existence of B/Z junctions. At higher amine concentrations, a DNA (Z-DNA) that is stiffer than B-DNA is observed. The Z-DNA induced by spermine is stiffer (runs more slowly on the gels) than that induced by the other amines. The spermine-DNA interaction is found to be very cooperative, whereas that of the cobalt amines is uncooperative. The kinetics of the B → Z transition with spermine at room temperature is very slow, whereas the cobalt amines induce it within seconds.
UR - http://www.scopus.com/inward/record.url?scp=0034544523&partnerID=8YFLogxK
U2 - 10.1039/b005801g
DO - 10.1039/b005801g
M3 - Article
AN - SCOPUS:0034544523
SN - 1463-9076
VL - 2
SP - 5469
EP - 5478
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
IS - 23
ER -