设计一个酵母SUMO标签,以消除内部翻译启动
Jamison D Law1,2, Yuan Gao1,3, Vicki H Wysocki1,2,3,4
1Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, USA.
Protein science : a publication of the Protein Society
|December 18, 2024
概括
一种新的SUMO标签变体,SUMONIT,在重组净化过程中防止截断蛋白质的产生. 这种修改通过消除内部翻译启动,确保了全长蛋白质的产量和纯度,特别是在同位体中.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 蛋白质工程是指蛋白质的工程.
背景情况:
- 重组蛋白质净化通常使用亲和度标签,如聚胺和可溶性增强剂,如小型无类修饰剂 (SUMO) 标签.
- 苏莫标签通常在净化后被删除,以防止干扰目标蛋白质的结构和功能.
- 由于Ulp1蛋白酶高效的SUMO标签裂变,N-终端His6-SUMO融合被广泛使用,可再生原生N-终端.
研究的目的:
- 通过使用His-6-SUMO融合来研究沙门氏菌同位体FraB脱糖酶的净化.
- 为了确定和解决在净化过程中观察到的截断蛋白质形成的原因.
- 开发一种改进的SUMO标签变体,增强蛋白质产量,纯度和均性.
主要方法:
- 在合适的宿主中,重组蛋白与N端His6-SUMO融合过度表达.
- 使用亲和性染色学净化重组蛋白质.
- 使用原生质谱学识别截断的蛋白质和分析SUMO标签序列.
- 局部定向突变产生SUMONIT变体,具有修改的Shine-Dalgarno序列.
主要成果:
- 含有Shine-Dalgarno (SD) 图案的真核SUMO标签序列导致了Escherichia coli*中截断的FraB蛋白的合成.
- 这些内部SD序列的突变产生了SUMONIT变体,它成功消除了截断的蛋白质生产.
- SUMONIT没有影响全长His6-SUMO-FraB的产量或Ulp1蛋白酶裂变的效率.
- 原生质谱检测揭示了包括切断蛋白质,氧化和蛋白酶抑制剂添加物在内的并发症,通常是低分辨率方法错过的.
结论:
- 在真核 SUMO 标签内的内部 Shine-Dalgarno 序列可以在细菌宿主中导致过早的翻译终止.
- SUMONIT变体有效地阻止了内部翻译,确保了全长重组蛋白的产生.
- SUMONIT是提高SUMO标记蛋白质的产量,纯度和同质性的宝贵工具,特别是同质分子.
- 原生质谱对于对重组蛋白质完整性的全面分析和识别净化工件至关重要.
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