Peptide synthesis catalysed by papain immobilised on polymer supports: effect of the macromolecular structure and reaction conditions on synthesis

Abstract

Papain immobilised on different types of polymeric supports was used for the synthesis of peptides in aqueous-organic solvent mixtures. The effects of the nature of the polymer support, degree of crosslinking, nature and length of the spacer grouping between the polymer backbone and the point of attachment of the enzyme, and reaction conditions like pH, concentration of nucleophile and the immobilised enzyme content on the course of the synthesis were investigated. Divinylbenzene-crosslinked polystyrene, divinylbenzenecrosslinked polyacrylamide and N,N'-methylene-bis-acrylamide-crosslinked polyacrylamide systems immobilised with papain were used for these studies. An increase in the length of the spacer arm and an increase in hydrophilicity invariably resulted in an increase in the yield of the peptide synthesis. Papain immobilised on polystyrene-PEG supports and tetraethyleneglycol-crosslinked polystyrene supports was determined to be more efficient in effecting peptide synthesis when compared to other polystyrene-based supports.