分子改造后酶法合成功能性低聚半乳糖的研究进展

Research progress of enzymatic synthesis of functional galacto-oligosaccharides after molecular modification

低聚半乳糖(Galactooligosaccharide,GOS)是近来年备受人们关注的功能性低聚糖之一,是β-半乳糖苷酶与乳糖发生转糖苷反应的主要产物。目前生产GOS的效率不高,是β-半乳糖苷酶与乳糖发生转糖苷反应的最终产物,自然界中含有该酶的菌株很多,但也由于来源广泛导致了相关的酶学特性各不相同;若想要满足人们的需求,需要采用酶工程等手段对酶进行分子改造,将该酶的某一特性进行提高,以得到目的菌株,该文中大致讲述了3种分子改造的方向,均能达到提升转苷率的目的;无论是利用哪种手段进行的分子改造,都需要了解目的酶分子活性中心的构造,有针对性地、通过结合理性与半理性设计而非盲目性的对酶进行分子改造。GOS的应用范围很广,在食品、医药及畜产领域中扮演着重要角色,有着不可忽视的地位,并且有很大的开发与挖掘空间。

Galacto-oligosaccharide(GOS)is one of the functional oligosaccharides that has attracted much attention in recent years.and the main product of the transglycosidase reaction betweenβ-galactosidase and lactose.There are many strains containing this enzyme in nature,but the related enzymatic properties are different due to the wide range of sources.To meet people’s needs,it is necessary to use enzyme engineering and other means to carry out molecular modification of the enzyme to improve a certain characteristic of the enzyme,so as to obtain the target strain.The direction of molecular modification is roughly described in this article in three methods,these methods can achieve the purpose of increasing the conversion rate.No matter which method is used for molecular modification,it is necessary to understand the structure of the molecular active center of the target enzyme,and targeted molecular modification of enzymes by combining rational and semi-rational design rather blind design.GOS has a wide range of applications and plays an important role in the food,pharmaceutical and livestock fields,and has a position that cannot be ignored.and there is a lot of development and mining space.