Xanthine oxidase inhibitory peptides derived from tuna protein: virtual screening, inhibitory activity, and molecular mechanisms

BACKGROUND There has been growing interest in the use of xanthine oxidase (XO) as a therapeutic agent to prevent gout and hyperuricemia. In the present study, XO inhibitory peptides were identified from tuna protein by virtual screening, and molecular docking was used to elicit the interaction mechanism between XO and peptides. RESULTS A novel tetrapeptide, EEAK, exhibited high XO inhibitory activity with an IC(50)of 173.00 +/- 0.06 mu M. Molecular docking analysis revealed that EEAK bound with the pivotal residues of XO's active sites (i.e., Glu802, Arg880, Glu1261) through two conventional hydrogen bond interactions, two attractive charge interactions, and one salt bridge. EEAK could also bind with the residues Phe649, Leu648, Lys771, Ser876, Phe914, and Thr1010 of XO. CONCLUSION This study suggested that conventional hydrogen bond interactions and electrostatic interactions play an important role in XO inhibition. The novel XO inhibitory peptide EEAK from tuna protein could be used as potential candidate for controlling gout and hyperuricemia. (c) 2020 Society of Chemical Industry

Automated summary

The study identified a novel tetrapeptide, EEAK, from tuna protein with high XO inhibitory activity, which binds to pivotal residues of XO's active sites through conventional hydrogen bond interactions and electrostatic interactions. This suggests that EEAK could serve as a potential candidate for treating gout and hyperuricemia.