How Do Phenolic Acids Change the Secondary and Tertiary Structure of Gliadin? Studies with an Application of Spectroscopic Techniques

• Published in: International journal of molecular sciences Vol. 23; no. 11; p. 6053
• Main Authors: Welc, Renata, Luchowski, Rafał, Kłosok, Konrad, Gruszecki, Wiesław I, Nawrocka, Agnieszka
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 27.05.2022; MDPI
• Subjects: Amino acids; Chains; Disaggregation; Fluorescence spectroscopy; Fourier transforms; FTIR technique; Gliadin; Gluten; Hydrocarbons; Hydrogen bonds; Hydrophobicity; Hydroxycinnamic acid; Lifetime; Molecular weight; Phenolic acids; Polypeptides; Polyphenols; Protein structure; Proteins; secondary structure; Spectrum analysis; Stiffness; Tertiary structure; time-resolved fluorescence; secondary structure; time-resolved fluorescence; FTIR technique; gliadin; phenolic acids
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms23116053

The effect of the chemical structure of selected phenolic acids on the molecular organization of gliadins was investigated with the application of Fourier Transform Infrared (FTIR) technique, steady-state, and time-resolved fluorescence spectroscopy. Hydroxybenzoic (4-hydroxybenzoic, protocatechuic, vanillic, and syringic) and hydroxycinnamic (coumaric, caffeic, ferulic, sinapic) acids have been used as gliadins modifiers. The results indicated that hydroxybenzoic acids due to their smaller size incorporate into spaces between two polypeptide chains and form a hydrogen bond with them leading to aggregation. Additionally, syringic acids could incorporate into hydrophobic pockets of protein. Whereas hydroxycinnamic acids, due to their higher stiffness and larger size, separated polypeptide chains leading to gliadin disaggregation. These acids did not incorporate into hydrophobic pockets.