Effect of PEAMA-g-PEG on the conformation of lysozyme by circular dichroism and florescence spectroscopy

Abstract

Conjugation of biological (peptides/enzymes) and synthetic polymers has potential applications in both medicine and biotechnology. We have shown in our previous article that the enzymatic activity of lysozyme was suppressed by the complex formation with a cationic smart copolymer, polyN,N-diethylaminoethyl methacrylate)-graft-poly(ethylene glycol) (PEAMA-g-PEG). In addition, the secondary structure of lysozyme was maintained. In the present study, tertiary structure of lysozyme were investigated using circular dichrosm (CD) and fluorescence spectroscopy. Near-UV CD spectral analysis clearly indicates that the complexation of lysozyme with PEAMA-g-PEG has almost no influence on the tertiary structure of lysozyme. Moreover, fluorescence spectrum of lysozyme and lysozyme complexed with PEAMA-g-PEG indicates the conformations of lysozyme were not disrupted.