Spectrophotometric studies on the interaction between (−)-epigallocatechin gallate and lysozyme

Various reported antibacterial activities of (−)-epigallocatechin-3-gallate (EGCG), the major polyphenol of green tea prompted us to study its binding with lysozyme. This has been investigated by fluorescence, circular dichroism (CD) and protein–ligand docking. The binding parameters were determined using a modified Stern–Volmer equation. The thermodynamic parameters are indicative of an initial hydrophobic association. The complex is, however, held together predominantly by van der Waals interactions and hydrogen bonding. CD studies do not indicate any significant changes in the secondary structure of lysozyme. Docking studies revealed that specific interactions are observed with residues Trp 62 and Trp 63.