ULTRASONIC ABSORPTION AND KINETICS OF CONFORMATIONAL CHANGE IN POLY-L-LYSINE

The velocity and attenuation of ultrasonic waves in aqueous solutions of poly-L-lysine have been measured as a function of frequency, temperature, and pH. No evidence of dispersion is found, but excess acoustic absorption, characteristic of a single process with relaxation time (2-4) × 10-8 sec, is observed. Arguments are offered in favor of the hypothesis that the observed relaxation is connected with a change in the chain conformation, perhaps with the helix-coil transition.