Nalivaeva N N, Turner A J
School of Biochemistry and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK.
Proteomics. 2001 Jun;1(6):735-47. doi: 10.1002/1615-9861(200106)1:6<735::AID-PROT735>3.0.CO;2-8.
Analysis of the expressed protein complement of cells requires knowledge of the diversity of post-translational modifications that can occur and which can be transient or permanent. The modifications range from amino acid changes through to the addition of macromolecules: lipid, carbohydrate or protein. Many variants of the common amino acids can occur, which can affect the structure or function of the protein. The major class of modification, however, is represented by glycosylation, N-linked, O-linked, or glycosylphosphatidylinositol(GPI)-linked. Such modifications have roles in protein stability and folding, targeting and recognition. Glycosylated proteins can be found in all cellular compartments and, intracellularly, O-GlcNAc modification is commonplace. Lipid modification of proteins (acylation, prenylation, GPI-anchoring) is also common, resulting in membrane association, and can play an important role in cell signalling. Targeting and turnover of proteins can also be mediated via covalent protein addition, for example by members of the ubiquitin family. Limited proteolysis as a post-translational modification will be discussed, focusing on the family of membrane protein secretases, in particular in relation to the Alzheimer's amyloid precursor protein. Finally, acetylcholinesterase will be used as a model example to illustrate the diversity of modifications occurring on a single protein.
对细胞中表达的蛋白质补体进行分析，需要了解可能发生的翻译后修饰的多样性，这些修饰可以是瞬时的或永久的。修饰范围从氨基酸变化到添加大分子：脂质、碳水化合物或蛋白质。常见氨基酸会出现许多变体，这可能会影响蛋白质的结构或功能。然而，主要的修饰类型是糖基化，包括N-连接、O-连接或糖基磷脂酰肌醇（GPI）连接。此类修饰在蛋白质稳定性、折叠、靶向和识别方面发挥作用。糖基化蛋白存在于所有细胞区室中，在细胞内，O-GlcNAc修饰很常见。蛋白质的脂质修饰（酰化、异戊二烯化、GPI锚定）也很常见，会导致膜结合，并且在细胞信号传导中可能起重要作用。蛋白质的靶向和周转也可以通过共价蛋白质添加来介导，例如通过泛素家族的成员。作为翻译后修饰的有限蛋白水解将被讨论，重点是膜蛋白分泌酶家族，特别是与阿尔茨海默病淀粉样前体蛋白相关的。最后，乙酰胆碱酯酶将作为一个模型示例来说明单个蛋白质上发生的修饰的多样性。
