Mechanism of interactions between egg protein derived tri‐peptides and cellular membrane by molecular dynamic simulation and isothermal titration calorimetry

TLDR: In this paper , the authors investigated the interaction of ACE inhibitory tri-peptides ADF, FGR, and MIR with the membrane using molecular dynamic simulation and isothermal titration calorimetry (ITC).

Abstract: Poor understanding of the absorption of food-derived angiotensin-converting enzyme (ACE) inhibitory peptides across the membrane limits their application in regulating and preventing hypertension. This study investigated the interaction of egg-derived ACE inhibitory tri-peptides ADF, FGR, and MIR with the membrane using molecular dynamic simulation and isothermal titration calorimetry (ITC). The structural variations in peptides during absorption were analyzed. The effect of peptides on the properties of membranes was also calculated during simulation. The binding mechanism between peptides and membrane was further characterized using ITC. The results showed that the structures of peptides were stable during simulation. Amino acid residues Arg, Phe, and Met contributed to the absorption of peptides across the membrane. Hydrogen bonds, electrostatic interactions and hydrophobic interactions stabilized the interaction of peptides with the membrane. The absorption of peptides ADF, FGR, and MIR into the membrane increased the membrane thickness of 0.78, 0.82, and 0.80 nm, respectively, and increased lipid lateral diffusion. The ITC results showed that peptides FGR and MIR binding to the membrane were spontaneous, entropy driven, and hydrophobic residues Phe and Met of peptides might contribute to peptides-membrane interactions, which was consistent with molecular dynamic simulation results.