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Rapid Generation of Amyloid from Native Proteins In vitro
Published on: December 5, 2013
在真核生物中生物合成胺提亚:将NAD转化为先进的中间体
Abhishek Chatterjee1, Christopher T Jurgenson, Frank C Schroeder
1Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA.
Journal of the American Chemical Society
|February 21, 2007
概括
研究人员确定了使用尼古丁胺氨酸二核酸 (NAD) 作为基质的提亚合成酶 (THI4) 的部分活性突变. 这一发现阐明了在真核生物中胺酸 thiazole 部分生物合成的早期步骤.
科学领域:
- 生物化学 生物化学
- 酶学 是一种酶学.
- 分子生物学分子生物学
背景情况:
- 来自Saccharomyces cerevisiae的醇合成酶 (THI4) 对于合成胺酸盐的醇部分至关重要.
- 野生型THI4与基化代谢物共净化,阻碍了解其催化机制的努力.
- 以前试图通过释放结合的代谢物来激活野生型THI4的尝试没有成功.
研究的目的:
- 识别和描述THI4的活性突变,以阐明其基质和催化机制.
- 在真核生物中研究胺 thiazole 部分生物合成的早期步骤.
主要方法:
- 用局部定向的突变发生法来创造C204A和H200NTHI4突变.
- 进行了酶活性测定,以检测代谢物释放和中间形成.
- 使用NMR光谱和ESI-MS实现了反应中间体的表征,在用ortho-phenylenediamine捕获后.
主要成果:
- 确定了两个部分活跃的THI4突变 (C204A和H200N).
- 这些突变物从尼古丁胺胺氨基二核酸 (NAD) 中释放了尼古丁胺胺的部分,产生ADP-ribose,随后ADP-ribulose.
- 在甘氨酸的存在下,突变分子形成了一种先进的中间体,被捕获并进行了表征.
结论:
- 尼古丁胺胺氨基二核酸 (NAD) 已被证实是THI4.4的基质.
- 这项研究阐明了在真核生物体中胺 thiazole 部分独特生物合成的初始步骤.
- 突变性特征提供了对 thiazole 合成酶的催化机制的新见解.
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