Optical Rotation of Oriented Helices. II. Calculation of the Rotatory Dispersion of the Alpha Helix

Abstract
The polarizability theory for the average optical rotation of a molecule has been generalized and has been used to calculate the optical rotation along specific directions in the molecule. The optical rotatory dispersion of polyglycine and polyalanine for light incident parallel and perpendicular to the helical axis has been calculated. The predicted dispersion is consistent with most experiments if a left‐handed helix is assumed for polybenzyl‐l‐glutamate and peptides with similar rotatory behavior. The average rotatory dispersion for a helix is not in general qualitatively different from that of a random coil.
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