丝素接枝含酪氨酸多肽对其酶促改性的影响

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

丝素中含约10%酪氨酸残基,但其可及度较低,影响了丝素蛋白的反应性。借助利用天然生物交联剂京尼平,将含酪氨酸多肽与丝素蛋白交联,提升酪氨酸酶催化丝素与外源氨基化合物接枝改性的效果;借助SDS-PAGE、FTIR和TG分析丝素分子量、结构与性能的变化,并评价酶催化ε-聚赖氨酸(ε-PL)在丝素表面接枝效率。研究表明,经京尼平处理后丝素蛋白的分子量增加,含酪氨酸多肽与丝素交联后,不仅使丝素膜材料热稳定性提升,也一定程度上增加了丝素蛋白膜材料机械性能,借助甲基橙比色法验证了接枝多肽能促进酪氨酸酶催化ε-PL在丝素表面接枝。基于京尼平法接枝含酪氨酸多肽为提高丝素的反应性提供了有效途径。

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.