FT-IR Analysis of pH and Xylitol Driven Conformational Changes of Ovalbumin–Amide VI Band Study

Globular protein ovalbumin (OV) contains four secondary structural conformations: α-helix, β-sheet, β-turn, and random coils. The transition between these conformational changes of proteins can be obtained by changes in various chemical and physical processes, including but not limited to heat, pressure, pH, adding cosolvent, and radiation exposure. The conformational changes are being well studied by Fourier transform infrared spectroscopy (FT-IR) spectroscopy, including various spectral regions such as amide A, amide B, and amide I to amide VII. The present study deals with the amide VI band (590–490 cm–1) analysis of OV conformational changes that occurred by varying pHs in the presence of cosolvent xylitol (XY). The obtained result indicates that α-helix to β-sheet transformation favor at pH 2, whereas β-sheet to β-turn transformation favor at pH 12. The neutral pH 7 favors both β-sheet as well as β-turn structures. These results confirmed that the noncovalent interactions contribute a major role in the conformational changes of OV.