POLARIZED LASER RAMAN STUDIES OF BIOLOGICAL POLYMERS

A group-theoretical analysis of the Raman tensor for helical polymers is given and illustrated for the Pauling a helix which possesses 18 residues in five turns. A detailed determination of the polarized Raman spectra is given for oriented α-helical poly-L-alanine fibers and for four polyribonucleotides in solution. Tentative assignments to A, E1, and E2 symmetry are made on certain Raman bands of poly-L-alanine based on the polarization of the Raman light. A detailed comparison of monomer and polymer bands are given for the four polynucleotides. A theory for the angular dependence of Raman light scattered from helical molecules is given.