Globin X: A highly stable intrinsically hexacoordinate globin.
Globin X: A highly stable intrinsically hexacoordinate globin.
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珠蛋白 X：高度稳定的本质六配位珠蛋白。
DOI：
10.1016/j.jinorgbio.2022.111976
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发表时间：
2022
影响因子：
3.9
通讯作者：
Miksovska,Jaroslava
中科院分区：
文献类型：
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作者：
Farhana,Rifat;Lei,Ruipeng;Pham,Khoa;Derrien,Valerie;Cedeño,Jonathan;Rodriquez,Veronica;Bernad,Sophie;Lima,FranciscoFernandez;Miksovska,Jaroslava
最近发现了脊椎动物球蛋白家族的几个新成员，它们具有传统五配位球蛋白中没有的独特结构特征。在这里，我们结合联合收割机的结构工具，以更好地理解和认识分子决定因素，有助于稳定的六配位珠蛋白X（GbX）从斑马鱼。pH诱导的解折叠数据表明GbX的稳定性增加，其中对于met GbXWT，pH为1.9 ± 0.1，对于met GbXC 65 A，pH为2.4 ± 0.1，对于GbXH 90 V，pH为3.4 ± 0.1。这些结果与使用GuHCl的GbX解折叠实验非常一致，其中对于metGbXWT和metGbXC 65 A构建体分别观察到Δ Gunf 13.8 ± 2.5 kcal mol− 1和16.3 ± 2.6 kcal mol− 1，并且对于GbXH 90 V测量到降低的稳定性，ΔGunf= 9.5 ± 3.6 kcal mol−1。metGbXWT和metGbXC 65 A还表现出高的热稳定性（熔点分别为118 °C和107 °C）。天然离子迁移率-质谱（IM-MS）实验显示天然结构蛋白质的窄电荷态分布（9-12+）特征;观察到天然状态的单个迁移率带。碰撞诱导展开IM-MS实验表明，在良好的协议与解决方案的研究，两个状态的转变。GbXWT保留了血红素在广泛的电荷状态，这表明强的相互作用之间的辅基和脱辅基蛋白。上述结果表明，除了二硫键和血红素铁六配位，其他结构决定因素增强该蛋白的稳定性。
Several novel members of the vertebrate globin family were recently discovered with unique structural features that are not found in traditional penta-coordinate globins. Here we combine structural tools to better understand and recognize molecular determinants that contribute to the stability of hexacoordinate globin X (GbX) fromDanio rerio(zebrafish). pH-induced unfolding data indicates increased stability of GbX with pHmidof 1.9 ± 0.1 for met GbXWT, 2.4 ± 0.1 for met GbXC65A, and 3.4 ± 0.1 for GbXH90V. These results are in good agreement with GbX unfolding experiments using GuHCl, where a ΔGunf13.8 ± 2.5 kcal mol−1and 16.3 ± 2.6 kcal mol−1are observed for metGbXWT, and metGbXC65A constructs, respectively, and diminished stability is measured for GbXH90V, ΔGunf= 9.5 ± 3.6 kcal mol−1. The metGbXWT and metGbXC65A also exhibit high thermal stability (melting points of 118 °C and 107 °C, respectively). Native ion mobility - mass spectrometry (IM-MS) experiments showed a narrow charge state distribution (9–12+) characteristics of a native, structured protein; a single mobility band was observed for the native states. Collision induced unfolding IM-MS experiments showed a two-state transition, in good agreement with the solution studies. GbXWT retains the heme over a wide range of charge states, suggesting strong interactions between the prosthetic group and the apoprotein. The above results indicate that in addition to the disulfide bond and the heme iron hexa-coordination, other structural determinants enhance stability of this protein.