Predicted role of particular phonons in the strand separation melting of the DNA double helix.
The frequency-dependent vibrational fluctuation of the hydrogen bonds around a nucleation defect for the strand separation melting of a DNA polymer poly(dG)-poly(dC) is studied using a modified self-consistent phonon theory. There are two critical frequency bands around the defect at 340 K which is near the temperature at which the hydrogen bonds in neighboring cells melt. The first band is between 60 cm-1 and 120 cm-1 which is essential for the melting proceeding in +z direction(3'----5' in the G backbone). The second is the band under 20 cm-1 which is important for the melting proceeding in -z direction.
Kim
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Y
Department of Physics, Purdue University, West Lafayette, Indiana 47907.
Prohofsky
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EW
D004278:DNA, Superhelical; D006358:Hot Temperature; D006860:Hydrogen Bonding; D009691:Nucleic Acid Denaturation; D014732:Vibration
D004278:DNA, Superhelical