确定循环核酸作为合因子生物合成中的神秘中间体
Bradley M Hover1, Anna Loksztejn, Anthony A Ribeiro
1Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, United States.
Journal of the American Chemical Society
|May 1, 2013
概括
研究人员确定了一种在辅因子 (Moco) 生物合成中的新型中间体, (8S) -3-3.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 酶学 是一种酶学.
背景情况:
- 辅因子 (Moco) 对所有生命形式的许多代谢过程至关重要.
- 莫科生物合成开始于瓜诺辛5'-三酸盐 (GTP) 转化为循环胺单酸盐 (cPMP).
- 已知细菌酶MoaA和MoaC催化了这一初始步骤,但它们的确切作用尚不清楚.
研究的目的:
- 阐明MoaA和MoaC在Moco生物合成的初始步骤中的特定功能.
- 为了隔离和结构性地描述由MoaA活动形成的中间产品.
主要方法:
- 在无氧条件下分离MoaA反应产物.
- 使用化学衍生,质谱学 (MS) 和核磁共振 (NMR) 光谱学进行结构阐明.
- 使用纯化MoaC及其人类同类MOCS1B的酶转化试验.
主要成果:
- 新型中间体 (8S) - 3',8-cyclo-7,8-dihydroguanosine 5'-triphosphate (3',8-cH2GTP) 被分离并进行了表征.
- 3',8-cH2GTP被MoaC和MOCS1B有效地转化为cPMP,这表明它的生理相关性.
- 证明MoaA可催化激素C-C键的形成,MoaC则参与了随后的松蛋白环的形成.
结论:
- 在Moco生物合成过程中,MoaA催化了一种独特的根基C-C键形成.
- MoaC在皮拉诺丁环合成所需的重组中起着重要作用.
- 这些发现澄清了MoaA和MoaC在这种必不可少的生物途径中的独特酶作用.
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