Elucidation of Protein−Lipid Interactions in a Lysozyme−Corn Oil System by Fourier Transform Raman Spectroscopy

Abstract

Lysozyme (25% in D2O, corn oil, and their emulsions (10% w/w oil/D2O solution) were examined by Fourier transform Raman spectroscopy. Emulsions showed three layers, namely, top oil, middle cream, and bottom aqueous layers. Raman spectral analysis revealed hydrophobic interactions involving both protein and lipid components. Compared to lysozyme in D2O, the difference spectrum obtained after subtraction of oil from the cream layer spectrum showed reduced intensity of tryptophan bands at 760, 1013, 1340, and 1360 cm(-)(1), reduced intensity ratio of the tyrosine doublet at 850 and 830 cm(-)(1), and increased intensity of the C-H bending band at 1455 cm(-)(1). Compared to corn oil, the difference spectrum after subtraction of lysozyme from the cream layer spectrum indicated decreased intensity at 2855 cm(-)(1) (lipid CH(2) symmetric stretch) and 3011 cm(-)(1) (unsaturated fatty acid hydrocarbon chain =C-H stretch) and a higher intensity ratio of the C-H stretching band at 2900 cm(-)(1) to bands at 2885 and 2933 cm(-)(1). Spectra of the top and bottom layers resembled corn oil and lysozyme, respectively, except for changes in the D2O band. Raman spectroscopy can be used to detect structural changes in proteins, lipids, and D2O due to protein-lipid interactions.

A Study on the Effect of Cinnamon and Cinnamaldehyde on Bovine Serum Albumin (Bsa) Protein by Using Ft-Raman Spectroscopy

“…The increase for the cinnamon BSA mixture suggests the participation of aliphatic amino acid residues in hydrophobic interactions (Howell & Li-Chan, 1996). Similar results have been reported by Howell et al (2001) when they studied lysozyme-corn oil proteinlipid interactions.…”

Influence of the addition of natural antioxidant from mate leaves (Ilex paraguariensis St. Hill) on the chemical, microbiological and sensory characteristics of different formulations of Prato cheese

“…The addition of 0.2 % of extract seems to inhibit the protein oxidation. Several authors relate that the interactions between lipids and proteins have a significant effect on oxidative reactions in food (Sarker et al 1995;Zamora et al 2000;Howell et al 2001). These oxidative phenomena can cause degradation, fragmentation or aggregation of the protein and enhancement of protein susceptibility (Decker 1998).…”

Evaluation of the stability of thighs and drumsticks boneless chicken under different conditions of industrial storage

“…A possible cause for the elevation of carbonyl groups after 12 months of storage at −6 and −12 °C could be related to lipid oxidation. Howell et al (2001) have already demonstrated that protein oxidation is related to lipid oxidation in meat products. Compared to lipid oxidation, the degradation of proteins by oxidants seems to be more complex and to produce an even greater multiplicity of reaction products and certain protein oxidation products may be active at water-lipid interfaces in meat (Jongberg et al, 2017).…”