Modification of structural and functional characteristics of casein treated with quercetin via two interaction modes: Covalent and non-covalent interactions

Dual Decoration of Ferritin Nanocages by Caffeic Acid and Betanin with Covalent and Noncovalent Approaches: Structure and Stability Analyses

“…Although the coupling of polyphenols can introduce nonpolar hydrophobic benzene rings into proteins, the introduction of hydrophilic hydroxyl groups of phenolic compounds can enhance the hydrophilicity of proteins, which is considered to be an essential factor affecting the hydrophobicity of proteins . Ke et al also obtained similar research results, and they found that after covalently bonding quercetin and casein, hydrophilic hydroxyl groups may be introduced, thus reducing the surface hydrophobicity of the protein . We inferred that, after covalent modification, some previously buried hydrophilic regions may be exposed and some hydrophobic residues blocked, resulting in changes in ferritin conformation, thus improving the hydrophilicity of ferritin.…”

“…37 Ke et al also obtained similar research results, and they found that after covalently bonding quercetin and casein, hydrophilic hydroxyl groups may be introduced, thus reducing the surface hydrophobicity of the protein. 38 We inferred that, after covalent modification, some previously buried hydrophilic regions may be exposed and some hydrophobic residues blocked, resulting in changes in ferritin conformation, thus improving the hydrophilicity of ferritin.…”

Effects of Chlorogenic Acid on Lowering IgE-Binding Capacity of Soybean 7S: Comparison between Covalent and Noncovalent Interaction

“…The amide I band (1600–1700 cm –1 ) is rich in information about the secondary structure of proteins, which is attributed to the stretching vibration of CO of proteins . The 7S had a maximum absorption peak at 3296 cm –1 in the amide A band, and the wavenumber of noncovalent and covalent interaction samples occurred red-shifts (3299, 3298, and 3297 cm –1 from N-0.3 to N-1, respectively; 3301, 3297, and 3304 cm –1 from C-0.3 to C-1, respectively), which indicated a reaction between free amino groups and polyphenols and there were hydrogen bonding interactions between CHA and 7S . The maximum absorption peak in the amide I band of 7S was located at 1644 cm –1 , and the absorption peaks of the noncovalent interaction (1645, 1641, and 1653 cm –1 from N-0.3 to N-1, respectively) and covalent interaction (1647, 1646, 1639 cm –1 from C-0.3 to C-1, respectively) had wavenumber shifts, suggesting that the secondary structure of the 7S has been affected and that the surrounding of CO has changed.…”

Egg White Protein–Proanthocyanin Complexes Stabilized Emulsions: Investigation of Physical Stability, Digestion Kinetics, and Free Fatty Acid Release Dynamics

“…As depicted in Figure 1c-e, the introduction of proanthocyanins decreases the intrinsic fluorescence compared to the egg white proteins. This phenomenon might illustrate that the introduced proanthocyanins' interaction with the egg white proteins induced the unfolding of the proteins' tertiary structure [17,18]. The revelation of aromatic amino acids within the protein framework could decrease the intrinsic fluorescence of proteins in the solution microenvironments.…”