Quantifying the Interaction between Copper-Zinc Superoxide Dismutase (Sod1) and its Copper Chaperone (Ccs1).
Quantifying the Interaction between Copper-Zinc Superoxide Dismutase (Sod1) and its Copper Chaperone (Ccs1).
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DOI：
10.4172/jpb.1000473
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发表时间：
2018-01-01
期刊：
影响因子：
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通讯作者：
Winkler, Duane D
中科院分区：
文献类型：
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作者：
Boyd, Stefanie D;Liu, Li;Winkler, Duane D
未成熟的铜锌超氧化物歧化酶（SOD 1）被其铜伴侣（Ccs 1）激活。Ccs 1提供一个单一的铜离子和催化氧化的亚基内的二硫键内的每个Sod 1单体通过一个机械模糊的过程。在这里，我们使用残基特异性荧光标记的未成熟的Sod 1量化的热力学的Sod 1Ccs 1相互作用，同时确定一个更完整的视图Ccs 1功能。Ccs 1优先结合一种完全不成熟的Sod 1形式，即金属缺乏和二硫键还原（E，E-Sod 1 SH）。然而，结合诱导的结构变化，促进高亲和力锌结合的Ccs 1结合的Sod 1分子。这进一步支持了Ccs 1可能在Sod 1成熟过程中发挥双重伴侣作用的观点。进一步的分析表明，除了铜依赖的作用，在Sod 1激活过程中，Ccs 1的N-和C-末端结构域也有协同作用，在确保Sod 1的识别和自己的活性构象。这些结果提供了新的和可测量的分析的分子决定因素指导Ccs 1介导的Sod 1激活。
Immature copper-zinc superoxide dismutase (Sod1) is activated by its copper chaperone (Ccs1). Ccs1 delivers a single copper ion and catalyzes oxidation of an intra-subunit disulfide bond within each Sod1 monomer through a mechanistically ambiguous process. Here, we use residue specific fluorescent labeling of immature Sod1 to quantitate the thermodynamics of the Sod1Ccs1 interaction while determining a more complete view of Ccs1 function. Ccs1 preferentially binds a completely immature form of Sod1 that is metal deficient and disulfide reduced (E, E-Sod1SH). However, binding induces structural changes that promote high-affinity zinc binding by the Ccs1-bound Sod1 molecule. This adds further support to the notion that Ccs1 likely plays dual chaperoning roles during the Sod1 maturation process. Further analysis reveals that in addition to the copper-dependent roles during Sod1 activation, the N- and C-terminal domains of Ccs1 also have synergistic roles in securing both Sod1 recognition and its own active conformation. These results provide new and measurable analyses of the molecular determinants guiding Ccs1-mediated Sod1 activation.