| Abstract: | The thermally induced conformational changes of poly-N5-(3-hydroxypropyl)-L -glutamine in water and in methanol–water (3:7 v/v) have been analyzed in terms of the Lifson-Roig theory. The transitions in both solvents can be described by using v = 0.017. The thermodynamic parameters for the random coil-to-helix transition of one amino acid residue at room temperature were found to be: in water, ΔH = ? 130 cal/mole and ΔS = ? 0.45 e.u.; in methanol–water (3:7 v/v), ΔH = ? 170 cal mole and ΔS = ? 0.45 e.u. The size distribution of helical segments is broad, and the results of numerical calculations are presented for three degrees of polymerization (DP = 100, 300, and 750). |
