Abstract:

The characteristics of the interaction between ovalbumin (OVA) and oleic acid (OA) were investigated by
using fluorescence spectroscopy, synchronous fluorescence spectroscopy, Fourier transform infrared spectroscopy and
circular dichroism spectrum. The results revealed that the interaction between OA and OVA quenched the fluorescence of
OVA, and the quenching mode changed from dynamic mode (without heating) to static mode (with heating). Hydrophobic
interaction and hydrogen bond played a dominant role in this interaction, and these forces were stronger with increasing
OA concentration. After interaction with OA, the fluorescence peaks of tyrosine and tryptophan residues in OVA were
blue shifted; α-helix and β-turn contents were decreased significantly, β-sheet content was increased significantly, while
random coil content was increased only at high OA concentration. In conclusion, OVA conformation was altered upon OA
interaction driven by hydrophobic interaction and hydrogen bond.

Key words: ovalbumin, oleic acid, fluorescence spectroscopy, Fourier transform infrared spectroscopy, circular dichroism spectrum