人的肠道微生物表达了功能上不同的内葡萄糖酶,以代谢相同的N-葡萄糖基质
Diego E Sastre1, Nazneen Sultana2,3, Marcos V A S Navarro4,5
1Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, USA. dsastre@emory.edu.
Nature communications
|June 15, 2024
概括
人类肠道细菌,如 Bacteroides thetaiotaomicron 拥有多种酶,如内-β-N-乙糖胺酶 (ENGases),以有效地分解高曼诺斯的 N-甘氨酸. 这些独特的酶在不同的条件下发挥最佳作用,使肠道中多功能营养物质的利用成为可能.
科学领域:
- 微生物学 微生物学
- 葡萄糖生物学 葡萄糖生物学
- 结构生物学 结构生物学
背景情况:
- 细菌类是人类关键的肠道微生物,它们具有用于甘氨酸降解的多糖利用位点 (PUL).
- 细菌菌体thetaiotaomicron通过表面内β-N-乙糖胺酶 (ENGase),BT3987.7.使用高曼诺斯 (HM) 的N-甘氨酸.
研究的目的:
- 发现和描述一种来自细菌菌体的新型ENGase (BT1285),该细菌体参与HM N-甘氨酸代谢.
- 通过BT1285阐明HM N-甘水解的分子机制,并比较其与BT3987.7的性能.
- 为了研究来自Alistipes finegoldii的HM处理内葡萄糖酶的功能性质.
主要方法:
- 用X射线晶体学和电子显微镜进行结构确定.
- 基于质谱的活性测定和功能特征的生物物理方法.
- 氨酸扫描突变发生以探测酶机制.
主要成果:
- 在B. thetaiotaomicron中发现了一种新的GH18家族ENGase,BT1285,编码在一个独特的PUL中.
- 与BT3987相比,BT1285具有更高的亲和力和更快的水解难以获得的HM N-糖,比BT3987更快.
- 在不同的环境条件下,BT1285和BT3987都具有最佳活动.
- 来自Alistipes finegoldii的内葡萄糖酶也表现出特定条件的功能.
结论:
- 人体肠道微生物利用具有条件特异性特性的独特的ENG酶来优化HM N-糖的代谢.
- 这种酶的多样性代表了一种进化策略,用于在胃肠道中有效地获取营养.
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