Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada.
Phytochemistry. 2010 Apr;71(5-6):502-7. doi: 10.1016/j.phytochem.2009.12.010. Epub 2010 Jan 11.
We have evaluated the effects of the proline homologue Aze (1) (azetidine-2-carboxylic acid) on growth of Escherichia coli strains used to over-express recombinant forms of murine myelin basic protein (rmMBP), and on the degree of misincorporation. Addition of Aze to minimal media resulted in severe diminution of growth rate, but rmMBP could still be produced and purified. Mass spectrometry indicated that a detectable proportion of the rmMBP produced had incorporated Aze instead of proline (Pro), to a maximum of three of eleven possible sites. Molecular modelling of a proline-rich region of rmMBP illustrated that the misincorporation of Aze at any site would cause a severe bend in the polypeptide chain, and that multiple Pro-->Aze substitutions would completely disrupt a poly-proline type II structure that has been conjectured to be functionally significant.
我们评估了脯氨酸类似物 Aze（1）（氮杂环丁烷-2-羧酸）对用于过表达鼠髓鞘碱性蛋白（rmMBP）重组形式的大肠杆菌菌株生长的影响，以及对错误掺入程度的影响。在基本培养基中添加 Aze 会导致生长速度严重下降，但仍可生产和纯化 rmMBP。质谱分析表明，所产生的 rmMBP 中有一定比例掺入了 Aze 而不是脯氨酸（Pro），在 11 个可能的位置中最多有三个位置。rmMBP 中富含脯氨酸的区域的分子建模表明，Aze 在任何位置的错误掺入都会导致多肽链严重弯曲，并且多个 Pro-->Aze 取代会完全破坏推测在功能上具有重要意义的聚脯氨酸 II 型结构。
