糖环对齐和动力学强调了细胞氨基和凝氨基对Pol η催化DNA合成的抑制
Caleb Chang1, Grace Zhou1, Christie Lee Luo1
1Department of Biosciences, Rice University, Houston, Texas, USA.
The Journal of biological chemistry
|May 12, 2024
概括
赛塔拉宾和吉姆西塔宾是抑制DNA合成的化疗药物. 它们的C2'糖修饰会影响DNA聚合酶活性,而细胞氨酸会比凝氨酸更大的抑制作用.
科学领域:
- 生物化学 生化学
- 分子生物学分子生物学
- 药物发现 药物发现 药物发现
背景情况:
- 核酸类类似物,如细胞氨酸和凝氨酸,是重要的抗病毒和化疗剂.
- 这些药物,尽管具有DNA合成功能,但阻碍了DNA扩展后合并.
- 糖C2'修饰影响聚合酶活性的确切机制在很大程度上仍未被阐明.
研究的目的:
- 为了研究C2'修改在细胞氨基酸和凝心氨酸对DNA聚合酶活性的影响.
- 阐明这些核酸相似物对DNA延伸抑制的机制基础.
- 为优化未来核类模拟药物开发提供见解.
主要方法:
- 采用了稳态动力学和静态/时间分辨率的X射线晶体学.
- 使用DNA聚合酶eta (Pol η) 作为一种模型酶系统.
- 分析了基质结合和DNA延伸动态在修饰核酸的存在下.
主要成果:
- 细胞氨基酸和凝氨基酸的C2'化学群适合在Pole的活性部位内,而不会阻断固体门.
- DNA聚合酶eta扩展了DNA的经过gemcitabine的效率低于自然基质,并且经过cytarabine的效率显著降低.
- 晶体结构显示,细胞胺的C2'-OH组诱导了不利的C2'-endo糖,阻碍了DNA延伸,而gemcitabine的原子破坏了必需的糖环形状转换.
结论:
- 细胞氨基酸和凝氨基酸中的C2'修改对DNA聚合酶 η活性和DNA延伸有不同的影响.
- 赛塔拉宾的抑制归因于锁定C2'-endo糖形状,而gemcitabine的作用源于糖环动态的改变.
- 这些发现提供了对化学疗法药物抑制和耐药性的机制理解,指导了改进的核类模拟药物的合理设计.
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