Maurice Wilkins Centre for Molecular Biodiscovery and School of Biological Sciences, University of Auckland, Auckland, New Zealand.
Trends Biochem Sci. 2011 Apr;36(4):229-37. doi: 10.1016/j.tibs.2010.09.007. Epub 2010 Nov 4.
The recent discovery of intramolecular isopeptide bonds formed between lysine and asparagine residues in certain bacterial cell-surface proteins represents a new component in nature's toolbox for stabilising proteins. Although isopeptide bonds are well known as intermolecular crosslinks in processes such as ubiquitylation, these intramolecular isopeptide bonds form autocatalytically during protein folding, as the reacting groups are brought together in a hydrophobic environment. First identified in the Ig-like pilin subunits of Gram-positive bacterial pili, these internal crosslinks provide stabilisation against chemical, thermal and mechanical stress and provide new opportunities for applications in biotechnology. The crucial role of structural biology and mass spectrometry in their discovery and characterisation raises the likelihood that further novel post-translational modifications resulting from intramolecular reactions in proteins await discovery.
最近在某些细菌表面蛋白中的赖氨酸和天冬酰胺残基之间形成的分子内异肽键的发现，代表了自然界用于稳定蛋白质的工具包中的一个新组件。虽然异肽键作为泛素化等过程中的分子间交联是众所周知的，但这些分子内异肽键在蛋白质折叠过程中会自动形成，因为反应基团在疏水环境中聚集在一起。首先在革兰氏阳性菌菌毛的 Ig 样菌毛亚基中被鉴定出来，这些内部交联提供了对化学、热和机械应力的稳定性，并为生物技术中的应用提供了新的机会。结构生物学和质谱在它们的发现和特性中的关键作用增加了这样一种可能性，即由于蛋白质内部反应而产生的进一步新颖的翻译后修饰有待发现。
