Mechanism of interaction between Portulaca oleracea L. extract and pork myofibrillar protein: Insights from spectroscopic and molecular docking analyses

The research aimed to elucidate the interaction and mechanism between the <i>Portulaca oleracea</i> L. extract (POE) and the pork myofibrillar proteins (MPs) from the perspectives of fluorescence spectroscopy and molecular docking. The results showed that POE significantly increased intermolecular hydrogen bonds and hydrophobic interactions in MPs (<i>P</i> < 0.05). Among the non-covalent forces between POE and MPs, hydrophobic interactions were dominant followed by hydrogen bonds. POE would cause a decrease in the endogenous fluorescence intensity of MPs, and the quenching type was static quenching. The binding molar ratio of POE to MPs was 1:1, and the formed complex exhibited high stability. The thermodynamic constants ∆G < 0, ∆H > 0, and ∆S > 0 indicated that the binding process between POE and MPs was spontaneous, with hydrophobic interactions being the primary driving force. Additionally, the nine most abundant compounds in POE were selected for molecular docking with myosin, and the binding energies were all negative, confirming that POE could spontaneously interact with MPs. The molecular docking results further demonstrated that hydrophobic interactions and hydrogen bonding were the main binding forces, with Leu270 potentially serving as a key amino acid residue in the interaction between POE and MPs. This study provides valuable insights into the molecular interactions between <i>Portulaca oleracea</i> L. extract and pork myofibrillar proteins, offering a theoretical basis for phenolic small molecule substances in regulating protein oxidation and potential applications in improving meat product quality.