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The dichroic tensor of flexible helices
Author(s) -
Wilson Robert W.,
Schellman John A.
Publication year - 1977
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.1977.360161006
Subject(s) - dichroic glass , chemistry , persistence length , dichroism , gaussian , tensor (intrinsic definition) , chain (unit) , circular dichroism , linear dichroism , random coil , limit (mathematics) , statistical physics , crystallography , molecule , computational chemistry , optics , quantum mechanics , physics , mathematical analysis , pure mathematics , mathematics , organic chemistry
A statistical theory of the linear dichroism of DNA‐like chains is presented for two models which are discrete versions of the wormlike coil. In the final form the linear dichroism of the entire chain is related directly to the dichroic properties of a chain segment (base pair). Though the derivations are somewhat complicated, the result [Eq. (28)] is simple and the required statistical parameters can be easily calculated for either model from measured values of the persistence length. In fact, for molecules as stiff as double‐stranded DNA, the results can be reduced with good accuracy to the form\documentclass{article}\pagestyle{empty}\begin{document}$$ \frac{{\Delta \varepsilon (chain)}}{{\Delta \varepsilon (segment)}} = \frac{{P_{\infty} }}{l}\frac{r^{2}}{{\langle r^2 \rangle_0 }} $$\end{document}showing that the “optical persistence” given on the left is directly proportional to the structural persistence, P ∞ / l. As in previous theories the results are restricted to chains in their Gaussian limit.