Contribution of asymmetric ligand binding to the apparent permanent dipole moment of DNA.
Despite its antiparallel symmetry, DNA often appears to possess a permanent electric dipole moment in transient electro-optical experiments. We propose that this may be due to the asymmetric binding of charged ligands to the DNA. We have used the fluctuating dipole theory of Kirkwood and Shumaker to calculate the contribution of asymmetric ligand binding to the electro-optic orientation function, and Monte Carlo computer simulation to calculate the reversing pulse behavior, as a function of ligand binding density. The results indicate that the effect should be observable even against the background of the sizable induced dipole moment produced by polarization of the counterion atmosphere.
Plum
G E
GE
Department of Biochemistry, University of Minnesota, St. Paul 55108.
Bloomfield
V A
VA
D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004247:DNA / Q000378:metabolism; D008024:Ligands
D008024:Ligands; D004247:DNA