Abstract: | The far-infrared absorption spectrum (40–400 cm?1) of solid pellets and films of several globular proteins (lysozyme, myoglobin, hemoglobin, serum albumin, ribonuclease, chymotrypsinogen, subtilisin) and of some representative polypeptides [nylon 66, poly (γ-benzyl L -glutamate)] have been investigated by using a Michelson interferometer. While polypeptides are known to present several peaks which can be assigned mostly to hydrogen-bond modes, all the investigated globular proteins display only one broad, intense baud in the 100–200 cm?1 region. The origin of this band, which persists even after denaturation or partial digestion, is discussed. |