## Abstract The CD spectra of a number of helical complexes formed by purine monomers and complementary pyrimidine polyribonucleotides have been observed over the range 200–400 nm. Each of these spectra is quite similar to that of the corresponding polymer–polymer helix. The spectra are evidently d
Circular dichroism of helical polynucleotides calculated by the linear response method
✍ Scribed by Stephen M. Redmann Jr.; William Rhodes
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1979
- Tongue
- English
- Weight
- 839 KB
- Volume
- 18
- Category
- Article
- ISSN
- 0006-3525
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Linear response theory in the decorrelation or random‐phase approximation is used to calculate the absorption and CD spectra of model helical polymers, including single‐stranded polyadenylic acid. The method, which makes use of infinite polymer selection rules for the linear response tensor, has the advantages that (1) only a few three‐dimensional matrices need be inverted; (2) spectral band shapes of the polymer arise naturally from those of the monomer, as well as from the geometry‐dependent interactions in the helix; and (3) the spectral dependence on geometrical factors of the helix is made transparent. It is found that the structure of the polymer CD spectrum depends critically on monomer bandshape. An asymmetric CD spectrum, similar to some experimental spectra, arises from either a Gaussian or a composite monomer band. Single‐stranded polyadenylic acid spectra are sensitive to helix geometry in the region 200–240 nm, in reasonable agreement with experimental spectra. This sensitivity arises from the 207‐nm monomer transition, and the results suggest that this region of the spectrum should be more fully exploited as a tool for helix geometry studies.
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