Recognition of the interaction between the bioactive peptide Val­Pro­Pro and the minimal promoter region of genes SOD and CAT using QCM-D and docking studies

Bioactive peptides are biomolecules involved in very diverse mechanisms in vivo. It has been reported that bioactive peptides play a very important role in the regulation of physiological functions such as oxidative stress, hypertension, cancer and inflammation. It's been reported that the milk derived peptide (VPP) prevents the progress of hypertension in different animal models and human beings with mild hypertension. It has also been shown that oral administration of VPP produces an anti-inflammatory effect in adipose tissue of mice models. Currently there are no reports on the possible interaction of VPP with the enzymes superoxide dismutase (SOD) and catalase (CAT), the main regulators of oxidative stress. This study analyzes the interaction between VPP and specific domains in the minimal promoter region of genes SOD and CAT in blood samples of obese children using a type QCM-D piezoelectric biosensor. We also used molecular modeling (Docking) to determine the interaction between the peptide VPP and the minimal promoter region of both genes. We detected with QCM-D the interaction of VPP with the nitrogenous bases sequences that comprise the minimal promoter region of both genes CAT and SOD. These experimental interactions were explained at atomic level by molecular docking simulations showing how the peptides are capable to reach the DNA structures by mean hydrogen bonds with favored free energy values. It is possible to conclude that the combined use of docking and QCM-D allows for the determination of the interaction of small peptides (VPP) with specific sequences of the genes.