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Low‐frequency infrared bands and chain conformations of polypeptides
Author(s) -
Masuda Yukio,
Fukushima Kunio,
Fujii Toyoko,
Miyazawa Tatsuo
Publication year - 1969
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.1969.360080108
Subject(s) - antiparallel (mathematics) , chemistry , amide , infrared , crystallography , infrared spectroscopy , bending , spectral line , chain (unit) , molecular physics , optics , physics , thermodynamics , organic chemistry , quantum mechanics , astronomy , magnetic field
Infrared spectra of polypeptides were measured in the region of 1800–400 cm −1 . For the α‐helical form, disordered form, and antiparallel‐chain β‐form, amide V band‐ arising from N‐H out‐of‐plane bending models were observed at 610–620, around 650, and 700–705 cm −1 , respectively, and amide V′ bands arising from N‐D out‐of‐plane bending modes were observed at 455–465, around 510, and a 515–530 cm −1 , respectively. These correlations are useful for conformation diagnoses, particularly for copolyamino‐acids or proteins which are not oriented. The nature of low‐frequency amide bands are discussed with reference to potential energy distributions calculated for the α‐helical form and β form.