铜第二协调球对细菌性多糖胺单氧化酶的催化性能和基质特异性的影响
Kelsi R Hall1,2, Maja Mollatt1, Zarah Forsberg1
1Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås 1432, Norway.
ACS omega
|June 3, 2024
概括
改变性多糖胺单氧酶 (LPMOs) 的第二协调球会影响它们的催化活性和稳定性. 特定突变可以增强基降解,这表明基质特异性进化的作用.
科学领域:
- 生物化学 生化学
- 酶学 是一种酶学.
- 结构生物学 结构生物学
背景情况:
- 性多糖体单氧化酶 (LPMOs) 是含铜的酶,对于分解性多糖体如纤维素和基至关重要.
- 低度聚烯机组使用保存的丁支架来结合铜,而第二个协调球体的变化会影响其活动.
- 已知的纤维素活性LPMOs在其第二个协调球体中具有His-Gln-Tyr或Arg-Glu-Phe图案.
研究的目的:
- 调查LPMOs中变化的第二协调球体残留物的功能影响.
- 了解His216-Gln219-Tyr221在*Ma*AA10B的催化机制和基质特异性中的相互关联的作用.
主要方法:
- 使用局部导向的突变发生法,将His-Gln-Tyr动机转换为*Ma*AA10B中的Arg-Glu-Phe动机.
- 在各种条件下进行了酶活性测定,包括减少剂驱动和H2O2驱动的反应.
- 评估了铜的反应性和酶稳定性,以评估突变的影响.
主要成果:
- 突变通常会降低酶的性能和稳定性,表明复杂的催化微调和第二球残留物的相互联系.
- Q219E突变显著增加了氧化酶活性,特别是在Tyr221.1.存在的情况下.
- 氧化酶活性的差异与多糖体降解相关,Q219E突变体显示出增强的酸盐降解.
结论:
- 第二个协调领域在调节LPMO活动,稳定性和基质特异性方面发挥着至关重要的作用.
- 在LPMOs中基质特异性的演变可能涉及基质结合表面和第二个协调球之间的相互作用.
- 向突变可以改变LPMO功能,为生物质转化提供了对酶工程的见解.
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