Molecular interactions between (-)-epigallocatechin gallate analogs and pancreatic lipase

PLoS One. 2014 Nov 3;9(11):e111143. doi: 10.1371/journal.pone.0111143. eCollection 2014.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Catechin / analogs & derivatives*
  • Catechin / chemistry
  • Catechin / pharmacology
  • Enzyme Activation / drug effects
  • Hydrodynamics
  • Kinetics
  • Molecular Structure
  • Pancrelipase / chemistry*
  • Pancrelipase / metabolism
  • Protein Binding
  • Protein Structure, Secondary / drug effects
  • Swine
  • Thermodynamics

Substances

  • Pancrelipase
  • Catechin
  • epigallocatechin gallate

Grants and funding

This work was funded by Beijing Municipal Natural Science Foundation (5142013). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.