Co-modification of amylase by acrolein with formaldehyde or methylglyoxal: Impact on enzyme function, structure, and cellular stress in two cell lines.

Reactive carbonyl species (RCS), such as acrolein (Acr), formaldehyde (FA), and methylglyoxal (MGO) are highly reactive aldehydes co-existing in processed foods and food materials. RCS may modify the digestive enzymes individually while whether they act together on the enzymes remains unknown. In this study, the co-action of RCS on α-amylase was studied. The results show that when Acr is present together with MGO or FA, they simultaneously modify amylase to form carbonylated proteins and inhibit the activity of amylase. The co-action of RCS increases the modification sites of amylase, enhances the fluorescent intensity of advanced glycation endproducts (AGEs) and protein oxidation products, and produces new protein adducts. Moreover, modified α-amylase inhibits cell viability, induces apoptosis, and triggers oxidative stress and inflammation via Keap1/Nrf2 and MAPK pathways.