| Abstract: | The quasielastic light scattering of poly-L -lysine HBr in aqueous solutions has been examined over a variety of pH values where the polymer is in different conformations. Analysis of the spectra demonstrates that as the pH is lowered, the polymer changes from an extended anisotropic from through a collapsed randomized state to a larger isotropic form. These data support the current view that the polymer undergoes a conformational change from an α-helical form to a “kinked” extended-coil conformation through an intermediate partially α-helical state in which internal packing of the helical portions occurs. Finally, a value for the rate of propagation of the unwinding of the α-helix has been obtained. |
