血清协调在酶P集群的结构和功能保护中的作用
Hannah L Rutledge1, Mackenzie J Field2, Jonathan Rittle1
1Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0340, United States.
Journal of the American Chemical Society
|November 29, 2022
概括
在酶中保存的血清残留物保护铁硫P团在氧化应激和铁限制下免受损伤. 这一发现揭示了胺配体在氧化还原蛋白中的新型保护作用.
科学领域:
- 生物化学
- 生物有机化学
- 酶的功能
背景情况:
- 酶通过通过P集群到活性位点的电子转移催化氨基合成.
- 在氧化过程中,P会发生形状变化,包括被保存的血清素/氨酸残留物结合.
- 在 Azotobacter vinelandii MoFeP (Av MoFeP) 中的一种血清连接体的突变不会影响标准生长或酶速率,从而质疑其必要性.
研究的目的:
- 在非理想条件下研究Av MoFeP中保存的βSer188残留物的保护作用.
- 评估βSer188在氧化应激和铁限制下对细胞生存的影响.
- 在体外评估βSer188Ala MoFeP变体的错误金属化倾向.
主要方法:
- 在低于最佳条件下 (氧化应激,铁限制) 描述 Azotobacter vinelandii (Av) βSer188Ala突变细胞生长.
- 在体外分析AvβSer188AlaMoFeP的金属交换和稳定性.
- 野生类型和突变的AvMoFeP之间的比较研究.
主要成果:
- 在暴露于过氧化 (氧化应激) 时,表达βSer188Ala MoFeP的Av细胞的存活率增加.
- 在缺少βSer188的情况下,在限制铁的条件下,Av的透生长受损.
- 在实验室中,βSer188Ala MoFeP变体表现出更大的P集团不金属化倾向.
结论:
- 在氧化应激和铁限制条件下,酸酶中保存的血清残留物 (βSer188) 对P集群起着至关重要的保护作用.
- 这项研究确定了先前未被识别的连蛋白在氧化还原蛋白中保护铁硫的功能.
- 这些发现扩大了非氨酸配体在金属蛋白的结构和功能完整性中的已知作用.
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