RESUMO
Insoluble dietary fibre from citrus peels (CIDF) was found to have adsorption and inhibitory effect on the activity of pancreatic lipase (PL). CIDF-400 exhibited the greatest adsorption and activity inhibition effect on PL. The fluorescence quenching spectra indicated that CIDF could quench PL through a dynamic quenching process induced by the electrostatic interactions with only one binding site between them. The synchronous fluorescence and three-dimensional fluorescence spectra showed that CIDF might combine with PL to induce the increase in hydrophobicity and the reduction in polarity of tyrosine (Tyr) and tryptophan (Try) residues, which further led to the conformational alternations of PL. Moreover, circular dichroism (CD) showed that CIDF altered the secondary structure of PL, decreased α-helical structure content, and increased ß-sheet structure content, potentially resulting in PL structure opening and its active site exposure. This study provides new perspectives for the application of CIDFs produced from agricultural waste in regulating lipid metabolism.
