微生物来源的果胶相关裂解酶的研究进展

Pectin-related lyases from microorganisms:a review

果胶是一种广泛存在于高等植物细胞壁中的大分子杂多糖,它主要由D-半乳糖醛酸、鼠李糖和阿拉伯糖等结构单元组成,在食品、化妆品和医药等领域用途较广。果胶裂解酶和果胶酸裂解酶同属于多糖裂解酶家族,都能利用反式消除裂解果胶分子骨架D-半乳糖醛酸间的α-1,4-糖苷键保护果汁特定香味的酯基团不发生改变,还不产生高毒性的甲醇。因此,这些裂解酶在果汁提取、苎麻脱胶和废水处理等工业领域具有广阔的应用前景。果胶底物的复杂结构导致了果胶酶的分类标准不一。本文从果胶底物的结构和特性,相关裂解酶的来源、序列分析、作用模式、三维结构及催化机制等方面进行综述,提高人们对微生物来源的果胶裂解酶和果胶酸裂解酶的系统认知。

As a structurally heterogeneous polysaccharide,pectin widely exists in the middle lamella and primary cell walls of higher plants.D-Galacturonic acid,rhamnose and arabinose are the predominant components of pectic substances,which have potential applications in food,cosmetics and medicine industries.Both pectin lyase and pectate lyase,which can effectively degrade pectin substrate,belong to the polysaccharide lyase family.They cleave pectin molecules through trans elimination reaction that mainly act on theα-1,4-glycosidic bond of the D-galacturonic acid backbone.In this way,the ester group responsible for the specific flavor of the juice will not be destroyed,and it rarely produces highly toxic methanol.Therefore,these lyases have been broadly applied for diverse industrial applications including textile industry,beverage industry,paper and pulp industry.The complicated structure of pectin leads to various classification criteria for pectinases.Although numerous research reports have been published,there are few reviews involved in pectin lyase and pectate lyase from microorganisms.This article aims to update the outdated reviews of these lyases.In this review,abundant information has been collected,including the structure and properties of pectin,the source,sequence analysis,mode of action,three-dimensional structure and catalytic mechanism of these lyases.