一种新型褐藻胶裂解酶及其截短体对酶学性质的影响  

A novel alginate lyase and the effect of its truncated form on enzymatic properties

作　　者：李辉梅 王文文 储建林 何冰芳[2] 吴斌[1] 钦松 LI Huimei;WANG Wenwen;CHU Jianlin;HE Bingfang;WU Bin;QIN Song(College of Biotechnology and Pharmaceutical Engineering,Nanjing Tech University,Nanjing 211800,China;School of Pharmaceutical Sciences,Nanjing Tech University,Nanjing 211800,China)

机构地区：[1]南京工业大学生物与制药工程学院,江苏南京211800 [2]南京工业大学药学院,江苏南京211800

出　　处：《生物加工过程》2024年第2期156-165,共10页Chinese Journal of Bioprocess Engineering

基　　金：国家重点研发计划(2021YFC2101500)。

摘　　要：褐藻寡糖是褐藻胶的降解产物,因独特的理化性质而具有抗肿瘤、促进生长和调节免疫等功效,受到广泛关注。为了挖掘更高效的褐藻胶裂解酶用于制备褐藻寡糖,对采集于海边土壤中的微生物进行筛选,以获得能够降解褐藻胶的菌株,并从其基因组中克隆表达出褐藻胶裂解酶,考察酶的催化特性。结果发现:从Paenibacillus lautus A2中鉴定出的一种新颖的褐藻胶内切酶AlgC2m,含有439个氨基酸,与PL7家族的AlgL仅有38%的最高序列一致性,其N端的碳水化合物结合模块(CBM32)和C端催化域(CD)通过一个连接子连接。AlgC2m和其截短体AlgC2m-CD降解褐藻酸钠的酶活分别为331.05和82.47 U/μmol,最适温度分别为45和30℃。另外,AlgC2m-CD对聚α-L-古罗糖醛酸(polyG)具有更明显的偏好性,酶解产物除二糖和三糖外,还有聚合度更高的四糖。Alginate oligosaccharides,the degradation products of alginate,display unique physical and chemical properties,as well as excellent biological effects including anti-tumor,growth promotion,immune regulation,thus they have received extensive attention in recent years.Herein,we report our efforts in exploring more effective alginate lyases for the preparation of alginate oligosaccharides.First,microorganisms collected from seaside soil were screened to obtain strains which could degrade alginate.Alginate lyase was then cloned and expressed from the genome of the target strain,and the corresponding catalytic properties were investigated.As a result,a novel endo-type alginate lyase AlgC2m was identified from Paenibacillus lautus A2,which contained 439 amino acids with only 38%of the highest sequence identity.The N-terminal carbohydrate binding module(CBM32)and the C-terminal catalytic domain(CD)were connected by a linker.AlgC2m and its truncated form AlgC2m-CD showed different enzymatic activities(331.05 and 82.47 U/μmol,respectively)and optimum temperatures(45 and 30℃,respectively).Moreover,the truncated form AlgC2m-CD demonstrated preference for the degradation of polyG,affording tetrasaccharides with higher degree of polymerization in addition to usual disaccharides and trisaccharides.

关 键 词：褐藻胶裂解酶 碳水化合物结合模块 非催化结构域 Paenibacillus lautus 产物分布 

分 类 号：Q814[生物学—生物工程]