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Dielectric relaxation and orientation of DNA molecules
Author(s) -
Hanss M.,
Bernengo J. C.
Publication year - 1973
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.1973.360120918
Subject(s) - polarizability , dipole , chemistry , dielectric , relaxation (psychology) , birefringence , ionic bonding , condensed matter physics , conductivity , polarization (electrochemistry) , chemical physics , dispersion (optics) , molecular physics , impurity , orientation (vector space) , molecule , nuclear magnetic resonance , optics , ion , physics , quantum mechanics , psychology , social psychology , organic chemistry , geometry , mathematics
A conductivity dispersion has been measured at very low frequencies (VLF) on several concentrated DNA solutions. By measuring simultaneously their electric birefringence decay, it is shown that the dielectric relaxation (which is related to the conductivity dispersion) is due to the molecular orientation. Different polarization mechanisms are discussed. It is concluded that the DNA polarizability measured in the VLF range can only be explained by the orientation of a permanent ionic dipole. It is suggested that such permanent dipoles could be caused by small differences in the ionic composition between the two molecular “ends;” the difference could either be stable (asymmetrical localization of protein impurities for instance) or transient (fluctuating dipoles explained by the Kirkwood‐Schumaker theory).