Binding mechanism of maltol with catalase investigated by spectroscopy, molecular docking, and enzyme activity assay.
Maltol is a flavor additive that is widely used in the daily diet of humans, and its biosafety attention is concomitantly increasing. Catalase (CAT) is an antioxidant enzyme to maintain homeostasis in the tissue's environment of human body and protect cells from oxidative damages. The adverse effects of maltol to CAT activity within mouse hepatocytes as well as the structural and functional changes of CAT on molecular level were investigated by multiple spectroscopy techniques, enzyme activity experiments, and molecular docking. Results suggested that when the maltol concentrations reached to 8 × 10-5 mol L-1 , the viability of hepatocytes decreased to 93%, and CAT activity was stimulated by maltol to 111% than the control group after exposure for 24 hours. Changes in CAT activity on molecular level were consistent with those on cellular level. The fluorescence quenching of CAT by maltol was static with the forming of maltol-CAT complex. Moreover, ultraviolet-visible (UV-visible) absorption, synchronous fluorescence, and circular dichroism (CD) spectra reflected that the presence of maltol caused conformational change of CAT and made the CAT molecule skeleton loose and increased α-helix of CAT. Maltol mainly bound with CAT through hydrogen bond, and binding site that is near the heme ring in the enzyme activity center did not interact with its main amino acid residues. This study explores the combination between maltol and CAT, providing references for evaluating health damages caused by maltol.
['Huo|Mengling|M|', 'Zhao|Lining|L|', 'Wang|Ting|T|', 'Zong|Wansong|W|', 'Liu|Rutao|R|0000-0001-7264-0531']
D001665:Binding Sites D055592:Biophysical Phenomena D002374:Catalase D002942:Circular Dichroism D006801:Humans D006860:Hydrogen Bonding D062105:Molecular Docking Simulation D011485:Protein Binding D011753:Pyrones D013050:Spectrometry, Fluorescence D013816:Thermodynamics
maltol catalase spectroscopy hepatocyte toxic effect