HRP酶促丝胶自交联及其膜材料的制备

HRP-catalyzed crosslinking of silk sericin and preparation of its membrane material

丝胶(SS)具有良好的生物相容性,但水溶性较高,材料成型性差,限制了其在生物材料领域的应用。文章通过辣根过氧化物酶(HRP)和过氧化氢(H 2O 2)协同催化丝胶蛋白分子间交联,并在此基础上制备丝胶蛋白膜材料。测定反应前后丝胶蛋白相对分子质量与二级结构变化,考察丝胶蛋白膜的水溶性、热性能及机械性能。结果表明:丝胶中酪氨酸残基能被HRP-H 2O 2体系催化氧化,引发丝胶蛋白分子间交联和相对分子质量增加,丝胶蛋白的二级结构由无定形结构向β构象转变。与未处理的丝胶膜相比,经酶促交联改性的丝胶膜水溶性下降,热性能和机械性能有所改善。

Silk sericin(SS)has the excellent biocompatibility.However,its high water solubility and poor formability limit its applications in the biomaterial field.In the present work,horse radish peroxidase(HRP)was used to catalyze the crosslinking of sericin in the presence of hydrogen peroxide(H 2O 2),and the membranes of cross-linked sericin were prepared on this basis.Changes in the relative molecular weight and secondary structure of silk sericin before and after the enzymatic reaction were determined,respectively.The properties of silk sericin membranes,including water solubility,thermal behavior and mechanical property were also examined.The results indicate that the HRP-H 2O 2 system could oxidize the tyrosine residues in sericins,thus initiating intermolecular crosslinking of sericin and increase in the relative molecular mass.The secondary structure of sericin is transformed toβconformation from amorphous structure.Compared with untreated sericin,water solubility of sericin modified by enzymatic crosslinking declined,and the thermal property and mechanical property improved.