肠道细菌需要单个硫酶才能获得结肠粘素
Ana S Luis1,2, Chunsheng Jin3, Gabriel Vasconcelos Pereira4
1Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA. ana.luis@medkem.gu.se.
Nature
|October 7, 2021
概括
肠道细菌如 Bacteroides thetaiotaomicron 使用硫酸酶来分解结肠粘液中的复杂的O-糖体. 这些硫酸糖在体外和体内都需要一个单一的关键硫酸酶.
科学领域:
- 微生物学
- 生物化学
- 葡萄糖生物学
背景情况:
- 人的结肠是密集的微生物群落,由粘液与上皮分离.
- 一些肠道细菌会代谢主要的粘液成分粘液糖蛋白,但参与O-糖降解的酶尚未完全理解.
- 结肠粘膜具有高度硫化O-甘氨酸,并且对这些甘氨酸活性的特定细菌硫酸酶仍未确定.
研究的目的:
- 识别细菌酶,特别是硫酸酶,对于降解结肠粘素O-甘氨酸至关重要.
- 阐明菌体 (Bacteroides thetaiotaomicron) 参与的酶机制和基质特异性.
- 研究这些硫酸酶在粘素降解中的体外和体内作用.
主要方法:
- 来自Bacteroides thetaiotaomicron的12个不同的硫酸酶的表征.
- 确定O-甘氨酸中各种硫酸盐结合的酶活性.
- 三种硫酸酶的X射线结晶学,以揭示特异性的结构基础.
- 在体外测定和体内研究,以评估硫酸酶在粘素利用中的作用.
主要成果:
- 在所有已知的O-甘氨酸硫酸结合上,Bacteroides thetaiotaomicron产生12个硫酸酶.
- 晶体结构为这些酶的基质特异性提供了机械洞察力.
- 一个单一的硫酸酶被认为是硫酸O- 甘氨酸在体外利用的必不可少的.
- 这种关键的硫酸酶在体内也起着重要作用.
结论:
- 硫酸酶对于Bacteroides thetaiotaomicron来说至关重要,可以利用结肠粘素O-甘氨酸.
- 一个单一的硫酸酶在体外和体内都对粘氨酸O-甘氨酸降解具有重要作用.
- 这些发现有助于我们更好地理解肠道细菌对粘素的降解,这与肠道殖民和炎症性肠道疾病有关.
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