在细胞染色体C氧化酶的对接位上结合联体:一个时间解析的步骤扫描里埃变换红外线研究
Constantinos Koutsoupakis1, Tewfik Soulimane, Constantinos Varotsis
1Department of Chemistry, University of Crete, 71409 Heraklion, Crete, Greece.
Journal of the American Chemical Society
|December 4, 2003
概括
一氧化碳 (CO) 暂时停靠在细胞染色体c氧化酶中的heme a(3) 附近,形成屏障,防止立即重新结合. 这揭示了呼吸系统酶中带运动的关键机制.
科学领域:
- 生物化学 生物化学
- 酶学 是一种酶学.
- 频谱学是一种光谱学.
背景情况:
- 像细胞染色体c氧化酶这样的酶激活小分子 (O(2),NO),需要了解连接体运动.
- 连接物运输涉及酶结构内的道和对接点.
- 来自T. thermophilus的细胞染色体c氧化酶ba(3) 催化了O(2) 和NO的减少.
研究的目的:
- 在环境温度下研究细胞染色体c氧化酶中的联结中间体.
- 阐明在血铜氧化酶中反应调节的结构基础.
主要方法:
- 时间分辨率步骤扫描里埃变换红外光谱学.
- 来自T. thermophilus的细胞染色体c氧化酶ba的CO-光解.
主要成果:
- 观察到光解CO被困在heme a(3) 酸盐附近的连接体对接点中.
- "停靠"的CO表现出B(1) 状态 (2131 cm(-1)) 持续35微秒.
- 在heme a(3) 附近的一个短暂的蛋白质屏障在从对接点释放后,在数毫秒内抑制了CO的重新结合.
结论:
- 细胞染色体c氧化酶利用特定的对接点来捕获短暂的连接体.
- 在对接点周围的蛋白质重组会对连接体重组产生暂时的障碍.
- 这种机制对于理解血铜氧化酶中的联体动力学和呼吸至关重要.
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