Premium
Far‐infrared spectra of sequential copolymers of amino acids with alkyl group side chains
Author(s) -
Itoh Koichi,
Katabuchi Hiroaki
Publication year - 1972
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.1972.360110806
Subject(s) - antiparallel (mathematics) , chemistry , copolymer , side chain , crystallography , infrared spectroscopy , alkyl , stereochemistry , alanine , beta sheet , infrared , polymer chemistry , amino acid , protein structure , polymer , organic chemistry , biochemistry , physics , quantum mechanics , magnetic field , optics
Far‐infrared spectra were measured for the sequential copolymers of amino acids with alkyl group side chains. The analysis of the spectra showed that ( L ‐Ala‐ L ‐Ala‐Gly) n , ( L ‐Ala‐Gly) n , ( L ‐Ala‐Gly‐Gly) n , ( L ‐Val‐ L ‐Ala‐ L ‐Ala) n , and ( L ‐Val‐ L ‐Ala) n , have the antiparallel pleated sheet structures and that the backbone conformations of ( L ‐Val‐ L ‐Val‐ L ‐Ala) n and ( L ‐Val‐ L ‐Val‐Gly) n are the same as that of poly‐ L ‐valine. The far‐infrared bands characteristic of the antiparallel pleated sheet structure were assigned on the basis of the result of the normal coordinate analysis of poly‐ L ‐alanine with this structure. The intersheet and interchain spacings of the sequential copolymers with the antiparallel pleated sheet structure were determined from the x‐ray powder‐diffraction patterns of these samples.