一个中的两个酶;两个酵母氧化素显示氧化应激依赖的转换从氧化酶到分子陪伴者功能
Ho Hee Jang1, Kyun Oh Lee, Yong Hun Chi
1Division of Applied Life Sciences, Gyeonsang National University, Chinju, 660-701, South Korea.
Cell
|May 28, 2004
概括
酵母百氧化素 (Prxs) 根据细胞应激来切换功能. 在氧化应激或热冲击下,这些蛋白质从过氧化酶转变为分子伴侣角色,增强酵母的生存能力.
科学领域:
- 生物化学 生物化学
- 细胞生物学 细胞生物学
- 压力反应应激反应
背景情况:
- 过氧化素 (Prxs) 是已知生物化学作用的酶,但它们的生理功能仍然不清楚.
- 细胞质酵母 Prxs,cPrxI和II,表现出结构多样性和不同的分子量 (MW).
研究的目的:
- 为了研究细胞质酵母百氧化素 (cPrxI和II) 的生理功能.
- 确定蛋白质结构和分子量如何影响Prxs.的双重功能.
- 阐明活性部位氨酸残留物在感知细胞应激和调解功能开关中的作用.
主要方法:
- 在不同条件下分析酵母氧化的结构和分子量.
- 在体外和体内对过氧化酶和分子伴侣活动的评估.
- 在酵母模型中诱导氧化应激和热冲击.
- 确定涉及应力感应和功能调节的关键残留物.
主要成果:
- 酵母cPrxI和II表现出双重过氧化酶和分子伴侣功能.
- 低MW形式的Prxs主要具有过氧化酶活性,而高MW复合体则作为伴侣.
- 氧化应激和热冲击诱导从低MW复合体转向高MW复合体,触发从过氧化酶到陪伴活动的功能切换.
- 活性过氧化酶位点残留物Cys{47}作为过氧化 (H2O2) 传感器,指导这些体内结构和功能变化.
- Prxs的陪伴者功能增强了酵母对热冲击的抵抗力.
结论:
- 酵母氧素具有氧化酶和伴侣活动之间的动态功能切换.
- 细胞应激条件通过结构复杂的形成决定了Prxs的主要功能.
- ) 对于感知H2O2和启动功能开关至关重要,有助于细胞应激耐受性.
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