当前位置: X-MOL 学术FEBS Open Bio › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Structural and functional insights into lysine acetylation of cytochrome c using mimetic point mutants
FEBS Open Bio ( IF 2.6 ) Pub Date : 2021-08-29 , DOI: 10.1002/2211-5463.13284
Inmaculada Márquez 1 , Gonzalo Pérez-Mejías 1 , Alejandra Guerra-Castellano 1 , José Luis Olloqui-Sariego 2 , Rafael Andreu 2 , Juan José Calvente 2 , Miguel A De la Rosa 1 , Irene Díaz-Moreno 1
Affiliation  

Post-translational modifications frequently modulate protein functions. Lysine acetylation in particular plays a key role in interactions between respiratory cytochrome c and its metabolic partners. To date, in vivo acetylation of lysines at positions 8 and 53 has specifically been identified in mammalian cytochrome c, but little is known about the structural basis of acetylation-induced functional changes. Here, we independently replaced these two residues in recombinant human cytochrome c with glutamine to mimic lysine acetylation and then characterized the structure and function of the resulting K8Q and K53Q mutants. We found that the physicochemical features were mostly unchanged in the two acetyl-mimetic mutants, but their thermal stability was significantly altered. NMR chemical shift perturbations of the backbone amide resonances revealed local structural changes, and the thermodynamics and kinetics of electron transfer in mutants immobilized on gold electrodes showed an increase in both protein dynamics and solvent involvement in the redox process. We also observed that the K8Q (but not the K53Q) mutation slightly increased the binding affinity of cytochrome c to its physiological electron donor, cytochrome c1—which is a component of mitochondrial complex III, or cytochrome bc1—thus suggesting that Lys8 (but not Lys53) is located in the interaction area. Finally, the K8Q and K53Q mutants exhibited reduced efficiency as electron donors to complex IV, or cytochrome c oxidase.

中文翻译:

使用模拟点突变体对细胞色素 c 赖氨酸乙酰化的结构和功能见解

翻译后修饰经常调节蛋白质功能。赖氨酸乙酰化在呼吸细胞色素c与其代谢伙伴之间的相互作用中尤其发挥着关键作用。迄今为止,已经在哺乳动物细胞色素c中明确鉴定了第8位和第53位赖氨酸的体内乙酰化,但对于乙酰化诱导的功能变化的结构基础知之甚少。在这里,我们独立地用谷氨酰胺替换了重组人细胞色素c中的这两个残基以模拟赖氨酸乙酰化,然后表征了所得 K8Q 和 K53Q 突变体的结构和功能。我们发现两种乙酰模拟突变体的物理化学特征大部分没有变化,但它们的热稳定性显着改变。主链酰胺共振的核磁共振化学位移扰动揭示了局部结构变化,固定在金电极上的突变体中电子转移的热力学和动力学表明氧化还原过程中蛋白质动力学和溶剂参与的增加。我们还观察到 K8Q(但不是 K53Q)突变略微增加了细胞色素c与其生理电子供体细胞色素 c 1 的结合亲和力(细胞色素c 1是线粒体复合物 III 或细胞色素bc 1的组成部分),因此表明 Lys8 (但 Lys53 除外)位于相互作用区域。最后,K8Q 和 K53Q 突变体作为复合物 IV 或细胞色素c氧化酶的电子供体的效率降低。
更新日期:2021-08-29
down
wechat
bug