设计关键的中央代谢酶以利用非正规的氧化还原辅因子
bioRxiv : the preprint server for biology
|July 15, 2025
概括
科学家们设计了大肠杆菌代谢中的一个关键酶,以使用一种新的辅助因子尼古丁胺胺单核酸 (NMN+),而不是其天然的NAD+. 这为生物合成创造了一个单独的氧化还原池,增强了代谢工程潜力.
科学领域:
- 生物化学 生物化学
- 代谢工程是代谢工程.
- 酵素工程是什么意思 酵素工程
背景情况:
- 中央代谢酶利用像NAD+和NADP+这样的氧化还原辅因子.
- 通过自然新陈代谢消耗降解功率限制了生物合成应用.
- 针对非正规的辅助因子的工程酶为控制的氧化还原分离提供了一种策略.
研究的目的:
- 为了工程 * Escherichia coli * 糖-3-酸脱酶 (GapA) 以利用尼古丁胺胺 mononucleotide (NMN+) 作为一个辅助因子.
- 为了实现与原生辅因子NAD+的直角性,用于不同的氧化还原池应用.
- 建立一个设计原则,用于工程辅因子在酶的特异性.
主要方法:
- 合理的酶设计和GapA的局部导向突变发生.
- 生物化学测试以测量NAD+和NMN+的酶活性.
- 罗塞塔计算机建模用于预测突变的结构效应.
主要成果:
- 鉴定了A180S变体,NMN+活性增加.
- 开发了双重突变G10R-A180S来降低NAD+活动.
- 工程三重突变G10R-A180S-G187Q (RSQ) 具有2.8 x 10^4折叠切换器在辅因子特异性到NMN+.
- RSQ变体显示了增强的四聚体稳定性,表明改善了辅因子结合.
结论:
- 为非正规辅助因子NMN+利用中心代谢酶 (GapA) 证明了成功的工程.
- 开发的酶变体对NMN+比NAD+具有很高的特异性.
- 发现的协因子结合口袋工程的设计原理可能适用于其他酶.
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