title: Molecular interactions between (-)-epigallocatechin gallate analogs and pancreatic lipase.
abstract: The molecular interactions between pancreatic lipase (PL) and four tea polyphenols (EGCG analogs), like (-)-epigallocatechin gallate (EGCG), (-)-gallocatechin gallate (GCG), (-)-epicatechin gallate (ECG), and (-)-epigallocatechin (EC), were studied from PL activity, conformation, kinetics and thermodynamics. It was observed that EGCG analogs inhibited PL activity, and their inhibitory rates decreased by the order of EGCG>GCG>ECG>EC. PL activity at first decreased rapidly and then slowly with the increase of EGCG analogs concentrations. α-Helix content of PL secondary structure decreased dependent on EGCG analogs concentration by the order of EGCG>GCG>ECG>EC. EGCG, ECG, and EC could quench PL fluorescence both dynamically and statically, while GCG only quenched statically. EGCG analogs would induce PL self-assembly into complexes and the hydrodynamic radii of the complexes possessed a close relationship with the inhibitory rates. Kinetics analysis showed that EGCG analogs non-competitively inhibited PL activity and did not bind to PL catalytic site. DSC measurement revealed that EGCG analogs decreased the transition midpoint temperature of PL enzyme, suggesting that these compounds reduced PL enzyme thermostability. In vitro renaturation through urea solution indicated that interactions between PL and EGCG analogs were weak and non-covalent.
authors.affiliation: Beijing Key Laboratory of Bioprocess, The Biorefinery Research and Engineering Center of the Ministry of Education of China, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China.
authors.forename: Shihui
authors.initials: S
authors.lastname: Wang
authors.affiliation: Beijing Key Laboratory of Bioprocess, The Biorefinery Research and Engineering Center of the Ministry of Education of China, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China.
authors.forename: Zeya
authors.initials: Z
authors.lastname: Sun
authors.affiliation: Beijing Key Laboratory of Bioprocess, The Biorefinery Research and Engineering Center of the Ministry of Education of China, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China.
authors.forename: Shengzhao
authors.initials: S
authors.lastname: Dong
authors.affiliation: Beijing Key Laboratory of Bioprocess, The Biorefinery Research and Engineering Center of the Ministry of Education of China, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Beijing Key Laboratory of Bioprocess, The Biorefinery Research and Engineering Center of the Ministry of Education of China, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000818:Animals; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D057446:Hydrodynamics; D007700:Kinetics; D015394:Molecular Structure; D020799:Pancrelipase / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D017433:Protein Structure, Secondary / Q000187:drug effects; D013552:Swine; D013816:Thermodynamics
chemical_list: D020799:Pancrelipase; D002392:Catechin; C045651:epigallocatechin gallate