Study on the interaction mechanism between ficin and a graft copolymer of carboxymethyl cellulose sodium salt and N-vinylimidazole using moleculardocking, fourier-transform infrared spectroscopy and raman spectroscopy

Abstract

Flexible molecular docking, Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy were used to investigate the interaction mechanism between ficin and a graft copolymer of carboxymethyl cellulose sodium salt and N-vinylimidazole. Functional groups and fragments of the graft copolymer as well as amino acid residues that form primary structure of enzyme and participate in interactions between ficin and a graft copolymer are identified. It is shown that Raman spectroscopy yields more complete information about graft copolymer fragments interacting with the protein than that FTIR can provide. It is found that the amino acid residues that form the active site of ficin are involved in the formation of hydrogen bonds and hydrophobic interactions with the graft copolymer leading to an increase in the proteolytic activity of the conjugated enzyme.