title: Study of poly-L-lysine conformations in aqueous methanol solution by using polarized Raman techniques.
abstract: Raman polarization measurements of the amide I band are reported in ionized poly-L-lysine dissolved in aqueous methanol. The observed changes with methanol concentration, attributed to changes in coil conformation and to the helix-coil transition, represent a novel method of measuring polymer conformation. Polarization measurements as a function of temperature yield values of the energy differences between rotational isomeric states in the coil. deltaH, of 8.8 +/- 0.7, 10.4 +/- 1.1 and 10.8 +/- 1.5 kJ/mol at methanol concentrations (v/v) of 85, 80 and 70% respectively. The stabilization energy of the helix is estimated at 9.3 kJ/mol.
mesh_terms: D007834:Lasers; D000432:Methanol; D010455:Peptides; D011107:Polylysine; D011487:Protein Conformation; D011489:Protein Denaturation; D012542:Scattering, Radiation; D013057:Spectrum Analysis; D013696:Temperature
chemical_list: D010455:Peptides; D011107:Polylysine; D000432:Methanol