Electric birefringence in solutions of high molecular weight ribonucleic acid.
The electric birefringence of low ionic strength solutions of high molecular weight ribonucleic acids from various sources was studied. RNA preparations with a high helical content were found to have negative electric birefringence as a result of the segment anisotropy of the helical portions of the RNA molecule. For completely unfolded molecules of RNA, the electric birefringence is positive and results from the orientation of the macromolecular coil. In intermediate cases, the observed electric birefringence is the sum of negative and positive birefringence. The negative birefringence is caused by the segment orientation of helical sections, and the positive birefringence is caused by the orientation of the macromolecular coil as a whole. Different relaxation times for the positive and negative birefringence permit the pulsed electric birefringence method to analyze these separate phenomena.
Golub
E I
EI
Institute of Biophysics, Academy of Sciences of the USSR, Moscow.
Nazarenko
V G
VG