特定突变逆转了腺酸的调节效应,并增加了它们在CBS域中含有酸酶的结合固态度
Viktor A Anashkin1, Elena A Kirillova1, Victor N Orlov1
1Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119899, Russia.
International journal of molecular sciences
|June 19, 2024
概括
调节性氨酸β-合成酶 (CBS) 域是蛋白质功能中的关键. CBS-PPase的突变发生揭示了改变连接体结合的特定残留物,影响了酶调节,并揭示了新的调节部位概念.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 酶学 是一种酶学.
背景情况:
- 调节性氨酸β-合成酶 (CBS) 域在蛋白质中普遍存在,但由于结构复杂性,它们的调节机制仍然不清楚.
- 微生物无机酸盐酶 (CBS-PPases) 是由腺酸盐和警报剂调节的四重酶,表现出复杂的全抑制和激活.
- 每个CBS-PPase子单元拥有两个CBS域,但仅与一个单-腺酸衍生物分子合作结合,这表明了复杂的调节部位相互作用.
研究的目的:
- 阐明控制Desulfitobacterium hafniense CBS-PPase通过单氨酸酸盐的全调节的关键蛋白质元素.
- 为了研究在CBS-PPase中观察到的"半位点"连接体结合史泰基几何学的分子基础.
主要方法:
- 使用局部导向的突变发生法,在D. hafniense CBS-PPase的CBS1域内替代了七个关键残留物.
- 用酶活性测定和异热定位热量计来描述11种CBS-PPase变异体与调节性配体 (ATP,ADP,AMP) 的相互作用.
主要成果:
- 特定的突变,如Lys100替代,逆转了ADP的作用,从抑制到激活.
- 在Lys95和Gly118的突变导致ADP的调节作用 (低度的激活剂,高度的抑制剂) 的度依赖转变.
- 突变显著增加了单氨酸酸盐结合固基度,在某些变体中有效地增加了两倍.
结论:
- 确定了关键氨基酸残留物 (Lys100,Lys95,Gly118),这些残留物决定了CBS-PPase中对ADP的全反应.
- 为CBS-PPase调节提供了支持"两个相互作用的调节位点的两个非相互作用对"模型的证据,解释了观察到的连接体结合石化学.
关键词:
全osteric调节的调节.合作性是一种合作性.囊氨酸β-合成酶域 囊氨酸β-合成酶域adenosine tetraphosphate 的使用方法酶调节酶的调节异热热量测量方法是异热量测量方法.更多相关视频
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