原核表达及细胞表面展示脯氨酸羟化酶改性鱼明胶

Fish Gelatin Modification Using Prokaryotic Expression and Cell Surface Display Proline Hydroxylases

鱼明胶次优的凝胶特性限制了其商业应用,酶催化改性鱼明胶有着绿色环保、安全高效等巨大优势,然而,目前报道的明胶改性酶较少,且多为蛋白质共价交联酶,易使明胶形成热不可逆凝胶。克隆出了两种增加胶原蛋白的非共价作用的脯氨酸羟化酶,对其进行原核表达。纯化后,分别对鱼明胶进行催化,结果表明两种酶具有改善鱼明胶胶强度和质构特性的效果。研究了钝齿棒杆菌的表面展示技术,将两种酶分别展示在钝齿棒杆菌表面,制备了一种以钝齿棒杆菌为载体的固定化酶体系,研究两种固定化酶体系对鱼明胶的改性效果。丰富了鱼明胶的催化酶体系,为鱼明胶的催化改性提供新思路。

The poor gel properties of fish gelatin limit its commercial application.Enzyme-catalyzed modification of fish gelatin has great advantages such as environmental friendliness,safety and high efficiency.However,there are few gelatin-modified enzymes reported at present,and most of them are covalent cross-linking enzymes,which easily make gelatin form thermal irreversible gel.In this study,two proline hydroxylases that increase the non-covalent action of collagen were cloned and expressed in prokaryotic cells.After purification,the fish gelatin was catalyzed respectively using two proline hydroxylases.The results show that the two enzymes have the effect of improving the gel strength and texture characteristics of fish gelatin.In addition,the surface display technology of Corynebacterium crenatum was studied.The two enzymes were displayed on the surface of C.crenatum,and an immobilized enzyme system with C.crenatum as the carrier was prepared for studying the modification effect of two immobilized enzyme systems on fish gelatin.This study has enriched the catalytic enzyme system of fish gel and provided a new idea for the catalytic modification of fish gelatin.