摘要
糖基化修饰是一类重要的翻译后修饰,对蛋白质的表达调控、折叠、分泌和功能等方面发挥着关键作用。酶是由活细胞产生的具有高度特异性和高效催化性的生物催化剂,酶的糖基化修饰对其生物催化特性和稳定性具有重要影响。研究糖基化修饰对酶蛋白的影响机制需要获取糖基化酶蛋白的结构,X-射线晶体衍射学是获得结构信息的重要技术手段,在糖基化酶蛋白的晶体衍射研究中,复杂、多样、不均一的糖基化修饰限制了该类酶的晶体生长,这是影响糖基化的酶蛋白结构解析的关键瓶颈问题。因此,如何提高糖基化的酶蛋白可结晶性是当前蛋白质结构研究的热点和难点。糖苷酶的去糖基处理、糖基转移酶抑制剂的引入和异源表达体系优化等手段都是当前研究领域提高糖基化的酶蛋白可结晶性的重要策略,这些手段可以在避免损害糖基化的酶蛋白稳定性和催化活性的同时提高其均一性。
Glycosylation is an important post-translational modification,which has important effects on expression regulation,folding,secretion and function of the proteins. Glycosylated modification mainly exists in eukaryotes,however it is found that some prokaryotes also possess that modification. Depending on the type of amino acid linked to the sugar chain,glycosylation can be divided into N-glycosylation and O-glycosylation.Enzymes are highly specific and efficient biocatalysts produced by living cells,which are proteins or RNA in chemical nature. The role of glycosylation in the internal structure and external function of enzymes has been a research hotspot in recent years,especially the influence on biocatalytic performance and stability. It has attracted much attention due to its far-reaching significance on the design and modification of enzymes. To understand the mechanism of influence made by glycosylation modification on enzyme structure and biocatalytic activity can provide ideas and directions for rational/semi-rational design and modification of enzyme molecules.X-ray crystallography is one of the main methods to study the structures of glycosylated enzymes,which combine X-ray diffraction and protein crystallography. However,complex sugar chains cause chemical and structural heterogeneity of glycosylated enzymes, which hinders crystal formation and crystal diffraction. Hydrolysis treatment with glycosidase, introduction of glycosyltransferase inhibitors and optimization of heterologous expression system are all important strategies to improve the crystallizability of glycosylated enzymes. These methods can improve the homogeneity of glycosylated enzymes while avoiding the damage to stability and catalytic activity of those.
作者
陈心怡
刘护
戴大章
李春
CHEN Xin-yi;LIU Hu;DAI Da-zhang;LI Chun(College of Chemistry and Chemical Engineering,Beijing 100081,China;State Key Laboratory of Bioreactor Engineering,East China University of Science and Technology,Shanghai 200237,China)
出处
《中国生物工程杂志》
CAS
CSCD
北大核心
2020年第3期154-162,共9页
China Biotechnology
基金
国家杰出青年科学基金(21425624)
国家自然科学基金(21706012)资助项目。
关键词
酶
蛋白质
结晶
糖基化
X-射线衍射
Enzyme
Protein
Crystallization
Glycosylation
X-ray crystallography
