N-乙酰氨基葡萄糖苷内切酶的功能与机制  

Endo-beta-N-acetylglucosaminidase:Possible Functions and Mechanisms

作　　者：芦鑫荣 童永亮 孔维溧 邹琳 沈旦枫 吕绍衔 刘瑞杰 张绍兴 张瑜芯 侯琳琳 孙桂芹[2] 陈力 LU Xin-Rong;TONG Yong-Liang;KONG Wei-Li;ZOU Lin;SHEN Dan-Feng;LU Shao-Xian;LIU Rui-Jie;ZHANG Shao-Xing;ZHANG Yu-Xin;HOU Lin-Lin;SUN Gui-Qin;CHEN Li(Key Laboratory of Medical Molecular Virology of Ministries of Education and National Health Committee,Department of Medical Microbiology and Parasitology,School of Basic Medical Sciences,Fudan University,Shanghai 200032,China;School of Medical Technology and Information Engineering,Zhejiang Chinese Medical University,Hangzhou 310053,China;College of Veterinary Medicine,Qingdao Agricultural University,Qingdao 266106,China)

机构地区：[1]复旦大学基础医学院病原生物学系,医学分子病毒学教育部/卫生健康委员会重点实验室,上海200032 [2]浙江中医药大学医学技术与信息工程学院,杭州310053 [3]青岛农业大学动物医学院,青岛266106

出　　处：《生物化学与生物物理进展》2024年第5期985-999,共15页Progress In Biochemistry and Biophysics

基　　金：国家重点研发计划(2021YFC2700801)资助项目。

摘　　要：N-乙酰氨基葡萄糖苷内切酶(endo-beta-N-acetylglucosaminidase,ENGase)广泛分布于各种生物中,主要通过降解错误折叠的糖蛋白,参与细胞和生命的调控。ENGase也是糖链编辑的有效工具酶,可专一性水解游离寡糖链及糖肽或糖蛋白上核心五糖的N-乙酰氨基葡萄糖(GlcNAc)之间的β-14糖苷键。其水解产物是寡糖链和一个GlcNAc,或带有一个GlcNAc的糖肽或糖蛋白。本文对ENGase的发现、分布、蛋白质结构、酶学反应及生物学功能进行阐述,为ENGase的生物学研究提供思路,为糖生物学与糖组学的应用研究奠定基础。Endo-beta-N-acetylglucosaminidase(ENGase)is widely distributed in various organisms.The first reported ENGase activity was detected in Diplococcus pneumoniae in 1971.The protein(Endo D)was purified and its peptide sequence was determined in 1974.Three ENGases(Endo F1-F3)were discovered in Flavobacterium meningosepticum from 1982 to 1993.After that,the activity was detected from different species of bacteria,yeast,fungal,plant,mice,human,etc.Multiple ENGases were detected in some species,such as Arabidopsis thaliana and Trichoderma atroviride.The first preliminary crystallographic analysis of ENGase was conducted in 1994.But to date,only a few ENGases structures have been obtained,and the structure of human ENGase is still missing.The currently identified ENGases were distributed in the GH18 or GH85 families in Carbohydrate-Active enZyme(CAZy)database.GH18 ENGase only has hydrolytic activity,but GH85 ENGase has both hydrolytic and transglycosylation activity.Although ENGases of the two families have similar(β/α)8-TIM barrel structures,the active sites are slightly different.ENGase is an effective tool for glycan detection and glycan editing.Biochemically,ENGase can specifically hydrolyze β-14 glycosidic bond between the two N-acetylglucosamines(GlcNAc)on core pentasaccharide presented on glycopeptides and/or glycoproteins.Different ENGases may have different substrate specificity.The hydrolysis products are oligosaccharide chains and a GlcNAc or glycopeptides or glycoproteins with a GlcNAc.Conditionally,it can use the two products to produce a new glycopeptides or glycoprotein.Although ENGase is a common presentation in cell,its biological function remains unclear.Accumulated evidences demonstrated that ENGase is a none essential gene for living and a key regulator for differentiation.No ENGase gene was detected in the genomes of Saccharomyces cerevisiae and three other yeast species.Its expression was extremely low in lung.As glycoproteins are not produced by prokaryotic cells,a role for nutrition and/or micro

关 键 词：N-乙酰氨基葡萄糖苷内切酶 N-糖基化 游离寡糖 糖链编辑 糖生物学 

分 类 号：Q55[生物学—生物化学]