Effect of Grafting of Tyrosine-Containing Peptide on Enzyme-Catalyzed Modification of Silk Fibroin

Abstract:

Silk fibroin contains 10% of tyrosine residues，however，the reactivity of fibroin is limited owing to the restricted accessibility. In this work，grafting of a tyrosine-containing polypeptide is carried out using a natural crosslinking agent of Genipin(GP)，aiming at promoting the tyrosinase-catalyzed reaction between fibroin and anime compounds. The changes in molecular weight，structure and performance are investigated by means of SDS-PAGE，FTIR and TG，are the efficiency of enzymatic grafting of ε-Poly-L-Lysine （ε-PL） is also concerned. The results indicate that the molecular weight for the fibroin proteins increas after GP treatment；the thermo stability and mechanical property for the fibroin-based membranes are also improved compared to the control. Based on methyl orange colorimetry，it is also verified that grafting of polypeptide could promote the tyrosinase-catalyzed coupling of ε-PL. It provides an efficient way to improve reactivity of fibroin via grafting of tyrosine-containing using GP.