The inhibition mechanism of luteolin on peroxidase based on multispectroscopic techniques

Luteolin, a plant-derived flavonoid, was found to exert effective inhibitory effect to peroxidase activity in a noncompetitive manner with an IC50 of (6.62 +/- 0.45) x 10(-5) mol L-1. The interaction between luteolin and peroxidase induced the formation of a static complex with a binding constant (K-sv) of 7.31 x 10(3) L mol(-1) s(-1) driven by hydrogen bond and hydrophobic interaction. Further, the molecular interaction between luteolin and peroxidase resulted in intrinsic fluorescence quenching, structural and conformational alternations which were determined by multispectroscopic techniques combined with computational molecular docking. Molecular docking results revealed that luteolin bound to peroxidase and interacted with relevant amino acid residues in the hydrophobic pocket. These results will provide information for screening additional peroxidase inhibitors and provide evidence of luteolin's potential application in preservation and processing of fruit and vegetables and clinical disease remedy. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

Luteolin effectively inhibits peroxidase activity in a noncompetitive manner, forming a static complex driven by hydrogen bond and hydrophobic interaction. Interaction between luteolin and peroxidase results in intrinsic fluorescence quenching, structural and conformational alterations.