Gornik Olga, Pavić Tamara, Lauc Gordan
University of Zagreb, Faculty of Pharmacy and Biochemistry, Zagreb, Croatia.
Biochim Biophys Acta. 2012 Sep;1820(9):1318-26. doi: 10.1016/j.bbagen.2011.12.004. Epub 2011 Dec 13.
Nearly all membrane and secreted proteins, as well as numerous intracellular proteins are glycosylated. However, contrary to proteins which are defined by their individual genetic templates, glycans are encoded in a complex dynamic network of hundreds of genes which participate in the complex biosynthetic pathway of protein glycosylation.
This review summarizes present knowledge about the importance of alternative glycosylation of IgG and other proteins.
Numerous proteins depend on correct glycosylation for proper function. Very good example for this is the alternative glycosylation of IgG whose effector functions can be completely changed by the addition or removal of a single monosaccharide residue from its glycans.
The change in the structure of a protein requires mutations in DNA and subsequent selection in the next generation, while even slight alterations in activity or intracellular localization of one or more biosynthetic enzymes are sufficient for the creation of novel glycan structures, which can then perform new functions. Glycome composition varies significantly between individuals, which makes them slightly or even significantly different in their ability to execute specific molecular pathways with numerous implications for development and progression of various diseases. This article is part of a Special Issue entitled Glycoproteomics.
几乎所有的膜蛋白和分泌蛋白，以及众多的细胞内蛋白都进行了糖基化修饰。然而，与由其各自的遗传模板定义的蛋白质不同，聚糖是由数百个基因组成的复杂动态网络编码的，这些基因参与蛋白质糖基化的复杂生物合成途径。
本综述总结了目前关于IgG和其他蛋白质可变糖基化重要性的知识。
许多蛋白质的正常功能依赖于正确的糖基化修饰。IgG的可变糖基化就是一个很好的例子，其效应功能可通过在聚糖上添加或去除单个单糖残基而完全改变。
蛋白质结构的改变需要DNA发生突变并在下一代中进行选择，而一种或多种生物合成酶的活性或细胞内定位即使发生轻微改变，也足以产生新的聚糖结构，进而执行新的功能。个体之间的糖组组成差异很大，这使得他们在执行特定分子途径的能力上略有不同甚至有显著差异，对各种疾病的发生和发展有诸多影响。本文是名为“糖蛋白质组学”的特刊的一部分。
