| Abstract: | The change in surface tension of solutions of poly-L -lysine in water has been studied as a function of temperature at various pH values. The changes at various temperatures have been correlated with changes in the circular dichroic spectra reflecting conformational change. In addition to the major transition at 50°C attributed to the conversion of the α-helical → β conformation, two other transitions have been observed at 30°C and 80°C. A minimum in the surface tension value was observed at pH 10, near the pK value for poly-L -lysine. It was concluded that at this pH the concentration of hydrophobic groups at the surface was a maximum. |
