ABSTRACT
Fraser and MacRae6 have reported important absorption bands for natural product proteins and nylon polyamide at 4870 cm-1 (2188 nm) resulting from a combination of the peptide absorptions at 3305 cm-1 (3026 nm), and 1540 cm-1
(6494 nm). For feather shafts, the authors report absorption bands at 4970 cm-1 (2012 nm) and 5040 cm-1 (1984 nm). A shoulder at 5040 cm-1 (1984 nm) was reported as resulting from side chain amide groups. For beta-keratin, the paper reports important absorption bands at 4600 cm-1
(2174 nm), 4850 cm-1 (2062 nm), and 4970 cm-1 (2012 nm). The authors were interested in studying the amorphous components of naturally occurring protein structures.
