Effect of Poly(vinyl alcohol) on the Thermally Induced Conformational Change of Poly(D-Glutamic acid)

摘要

In relation to denaturation of proteins, thermally induced conformational change of poly(D-glutamic acid) was studied in the presence of poly(vinyl alcohol) at low pH, where poly(D-glutamic acid) undergoes a helix-to-モ transition without any other polymer. In a dilute solution, poly(vinyl alcohol) enhanced the メ-to-モ1 transition of poly(D-glutamic acid) due to intermolecular interaction between the two polymers. On the other hand, this conformational change was interrupted to a large extent in a concentrated solution, due to the interpenetration of poly(vinyl alcohol) chain into poly(D-glutamic acid) chain which prevented the intramolecular association of poly(D-glutamic acid) chain. A conformational change from モ1 to モ2 of poly(D-glutamic acid) was observed for the films obtained by casting during annealing the mixture solutions. The モ2 content in the cast film increased with increasing poly(vinyl alcohol) content in the mixture.