Formation of protein-anthocyanin complex induced by grape skin extracts interacting with wheat gliadins: Multi-spectroscopy and molecular docking analysis

• Published in: Food chemistry 2022-08, Vol.385, p.132702-132702, Article 132702
• Main Authors: Guo, Ziqi, Huang, Yuqi, Huang, Jian, Li, Shuyi, Zhu, Zhenzhou, Deng, Qianchun, Cheng, Shuiyuan
• Format: Article
• Language: English
• Subjects: Anthocyanins - chemistry; Gliadin; Gliadin - chemistry; Grape skin anthocyanin extracts; Interaction; Molecular docking; Molecular Docking Simulation; Plant Extracts - metabolism; Spectroscopy; Spectrum Analysis; Triticum - chemistry; Vitis - chemistry
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2022.132702

[Display omitted] •Binding with anthocyanins altered the secondary structure of gliadin.•Hydrophobic interactions were dominant for the formation of Gli-GSAE complexes.•Different Gli-GSAE complexes possess different binding rates. In order to broaden the application of grape skin anthocyanin extract (GSAE) in flour products, the interaction of gliadin (Gli) and GSAE were investigated. Seven anthocyanin components from GSAE were identified by HPLC-MS2, which could form complexes with Gli having different binding rates based on UV, FTIR and HPLC analysis. The fluorescence quenching experiment showed that GSAE was capable of efficiently quenching the intrinsic fluorescence of Gli through hydrophobic interactions, and the binding parameters were near to one unit at the given temperatures. Additionally, GSAE binding changed the conformational properties of Gli, increasing α-helix and β-turn content, but decreasing β-sheet and irregular coil content. The molecular docking suggested that Gli possessed various binding sites bound with different anthocyanin monomers, mainly depending on hydrogen bonds and hydrophobic interactions. These findings further proved the formation of Gli-GSAE complex, indicating the potential of anthocyanins as natural colorant.