Effect of Temperature on the Conformation of Extended α-Keratin

Attenuated total reflection Fourier transform infrared (ATR/FT-IR) spectra of wet horse hair α-keratin indicate that the conformation of extended α-keratin is affected by the water temperature. Extension of the wet horse hair in 21 °C water gives rise to parallel β-sheet structures, thus suggesting that the original α-helical structure is also parallel. In contrast, extension of the wet horse hair α-keratin in 95 °C water gives rise to anti-parallel β-sheet structures (consistent with reported literature where X-ray diffraction was used), suggesting that disulfide interchange and/or increased chain mobility at elevated temperatures plays a role in altering the secondary structure.