Circular Dichroism Studies of Secondary Structure of Peptides

Abstract

The optical activity characteristic of organic molecules is a result of the absorption of light as electrons are promoted to higher molecular orbitals. In UV-visible spectroscopy, the transition process is described by the Beer-Lambert Law, A = εcd, in which A is the experimentally measured absorbance, ε is the extinction coefficient, c is the molar concentration of solute, and d is the path length. Absorbance, A, is plotted vs energy or wavelength of the light.