Optical rotatory disperson

With heating from 5 to 45°C, thermal changes in conformation in the major /3-casein are observed by spectral methods (Garnier 1966). From measurements of the optical density at 286 nm and of the specific optical rotation at 436 nm, a rapidly reversible endothermic transition (AH 30 kcal/mole) with a half-transition temperature of 23-24°C is observed. The optical rotatory dispersion data suggest a decrease in the poly-L-proline II structure (12 to 5%) and a slight increase in a-helix (11 to 16%) with increasing temperature. This transition probably occurs prior to association, since it is rapid, and the carboxyacyl derivative of the monomer, which does not polymerize with increasing temperature, also demonstrates the optical rotatory disperson thermal transition. 

Optical rotatory disperson is the change of optical rotation with wavelength. The data for optical rotatory dispersion are often analyzed in terms of the Drude (1900) equation ... 

---