Mechanism of protein digestion inhibition by malondialdehyde-mediated oxidation in terms of molecular actions and structural changes

This study investigated the molecular mechanism of malondialdehyde (MDA)-mediated oxidation affecting the digestive properties of myofibrillar proteins (MP) in golden pomfret using an in vitro static digestion model combined with multispectral and molecular docking techniques. It has been found that MDA hinders the digestion of proteins, resulting in a tendency to show a decrease in the digestibility of proteins. Using a multispectral technique, it was found that MDA could disrupt the structure of proteins, causing aggregation and precipitation of proteins. Moreover, static quenching occurred during the interaction between MDA and MP, as well as changes in the microenvironment of MP. In addition, thermodynamically analyzed, the type of binding force between the two is hydrophobic. However, the binding of MDA to MP was not stable. Using the molecular docking technique, it was found that MDA could bind to the enzymatic site on MP. These results suggest that MDA is hindering digestion by disrupting the enzymatic site on MP. This work contributes to the understanding of the relationship between changes in protein properties during meat processing and the variability of digestion, thereby improving the meat quality of aquatic products.