Thermal destabilization mechanism of cytochrome c' from psychrophilic Shewanella violacea
Thermal destabilization mechanism of cytochrome c' from psychrophilic Shewanella violacea
复制标题
嗜冷希瓦氏菌细胞色素 c 的热失稳机制
DOI：
10.1093/bbb/zbab007
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Sambongi Yoshihiro
中科院分区：
文献类型：
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作者：
Sakaguchi Riku;Fujiyoshi So;Wakai Satoshi;Yamanaka Masaru;Sambongi Yoshihiro
Cytochromec′是一种存在于革兰氏阴性菌中的一氧化氮（NO）结合血红素蛋白。嗜冷希瓦氏菌紫色细胞色素′（SVCP）的热稳定性低于其它2种希瓦氏菌的同源物，表明SVCP中积累了适应低温的热失稳机制。为了在氨基酸水平上理解这种机制，在此检查了使用2种同源物建模的SVCP变体的稳定性和功能。这些变体表现出增加的稳定性，并且它们与野生型类似地结合NO。SVCP稳定性的脆弱性可能归因于亚基界面上较少的氢键，更灵活的环结构，以及蛋白质表面上较少的盐桥，这似乎是其不稳定的机制。该研究为控制嗜冷蛋白的稳定性而不破坏其功能提供了一个实例。
Cytochromec′ is a nitric oxide (NO)-binding heme protein found in Gram negative bacteria. The thermal stability of psychrophilicShewanella violaceacytochromec′ (SVCP) is lower than those of its homologues from other 2 psychrophilicShewanellaspecies, indicating that thermal destabilization mechanism for low-temperature adaptation accumulates in SVCP. In order to understand this mechanism at the amino acid level, here the stability and function of SVCP variants, modeled using the 2 homologues, were examined. The variants exhibited increased stability, and they bound NO similar to the wild type. The vulnerability as to the SVCP stability could be attributed to less hydrogen bond at the subunit interface, more flexible loop structure, and less salt bridge on the protein surface, which appear to be its destabilization mechanism. This study provides an example for controlling stability without spoiling function in psychrophilic proteins.