Acinetobacter baumannii K239囊多糖体包括与K86结构相关但由不同的Wzy聚合酶形成的不同链接连接的肝糖单元
Anastasiya A Kasimova1, Alexander S Shashkov1, Mikhail M Shneider2
1N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia.
International journal of biological macromolecules
|February 9, 2024
概括
阐明了Acinetobacter baumannii K239囊多糖体 (CPS) 结构,揭示了由于特定基因而与K86 CPS的差异. 这种结构变异会影响细菌的易感性.
科学领域:
- 微生物学 微生物学
- 碳水化合物化学 碳水化合物化学
- 结构生物学 结构生物学
背景情况:
- 杆菌 (Acinetobacter baumannii) 是一种机会性病原体,以其多种囊多糖 (CPS) 类型而闻名.
- 了解CPS结构对于开发向治疗和诊断至关重要.
研究的目的:
- 为了确定从Acinetobacter baumannii分离MAR19-4435中K239囊多糖 (CPS) 的详细结构.
- 将K239 CPS结构与相关的K86 CPS结构进行比较,并研究它们差异的遗传基础.
- 评估结构变异对菌体易感性的影响.
主要方法:
- 孤立的K239 CPS的糖分分析.
- 一维和二维H和C核磁共振 (NMR) 光谱用于结构阐明.
- 对CPS生物合成基因集群 (gtr和wzy基因) 的生物信息分析.
- 对细菌 (APK86) 敏感性的评估.
主要成果:
- K239 CPS是由含有l-rhamnose,d-glucuronic acid和N-acetyl-d-glucosamine的分支式肝糖重复组成的.
- K239的结构不同于K86 CPS,在K-单元链接中涉及的l-rhamnose残留物的2,3-置换模式中.
- 基因分析显示,不同的甘氨基转移酶 (gtr221与gtr80) 和聚合酶 (wzyKL239与wzyKL86) 是负责这些结构差异的基因.
- 一个新的WzyKL239聚合酶被确定,在K239.9中形成了特定的β-d-GlcpNAc-(1→2)-l-Rhap链接.
- Acinetobacter baumannii MAR19-4435表达K239 CPS对APK86菌有抗性,与表达K86 CPS的菌株不同.
结论:
- 对K239 CPS的结构阐明为Acinetobacter baumannii表面结构的多样性提供了见解.
- 特定的葡萄糖转移酶和聚合酶基因决定了K239 CPS的独特结构特征.
- 在l-rhamnose替代中观察到的差异显著影响了Acinetobacter baumannii对特定菌的敏感性,突出了CPS结构在宿主-病原体-菌体相互作用中的作用.
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