Spin cascade and doming in ferric hemes: Femtosecond X-ray absorption and X-ray emission studies
Spin cascade and doming in ferric hemes: Femtosecond X-ray absorption and X-ray emission studies
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三价铁血红素中的自旋级联和隆起：飞秒 X 射线吸收和 X 射线发射研究
DOI：
10.1073/pnas.2009490117
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发表时间：
2020
影响因子：
11.1
通讯作者：
M. Chergui
中科院分区：
文献类型：
--
作者：
C. Bacellar;D. Kinschel;G. Mancini;R. Ingle;J. Rouxel;O. Cannelli;C. Cirelli;G. Knopp;J. Szlachetko;F. Lima;S. Menzi;G. Pamfilidis;K. Kubicek;D. Khakhulin;W. Gawelda;A. Rodriguez;M. Biednov;C. Bressler;C. Arrell;Philip J. M. Johnson;C. Milne;M. Chergui
结构-功能关系是生物学的核心，而结构动力学是由电子变化驱动的。亚铁血红素蛋白质的圆顶，这是核心的血红蛋白的呼吸功能，从人口的高自旋状态。然而，对于铁血红素蛋白，圆顶被排除在外。在这里，我们表明，高自旋状态的光激发铁细胞色素c的人口，我们提出的证据圆顶。我们还得出结论，光或热激活的圆顶发生在各种各样的铁血红素蛋白，要求更深入地了解其在各自的功能中的作用。结构-功能关系是生物学的核心，主要的蛋白质变形与特定的功能相关。对于亚铁血红素蛋白，圆顶与血红蛋白和肌红蛋白的呼吸功能有关。细胞色素c（Cytochrome c，Cyt c）是一种重要的电子传递蛋白。在其亚铁形式，它经历配体释放和拱光激发后，但其铁的形式不释放远端配体，而返回到基态已归因于热弛豫。在这里，通过结合飞秒Fe Kα和Kβ X射线发射光谱（XES）与Fe K边X射线吸收近边结构（XANES），我们证明了铁的Cyt c的光循环完全是由于铁离子的激发自旋态之间的级联，导致铁血红素进行拱起，我们确定。我们还认为，这种模式是常见的铁血红素蛋白质的多样性，提出了这样的蛋白质的圆顶的生物相关性的问题。
Significance The structure–function relationship in central to biology, while the structural dynamics are driven by electronic changes. Doming of ferrous heme proteins, which is central to the respiratory function of hemoglobin, ensues from populating high-spin states. However, for ferric heme proteins, doming was excluded. Here, we show that high-spin states are populated in photoexcited ferric cytochrome c, and we present evidence for doming. We also conclude that photo- or thermally activated doming occurs in a wide variety of ferric heme proteins, calling for a deeper understanding of its role in their respective functions. The structure–function relationship is at the heart of biology, and major protein deformations are correlated to specific functions. For ferrous heme proteins, doming is associated with the respiratory function in hemoglobin and myoglobins. Cytochrome c (Cyt c) has evolved to become an important electron-transfer protein in humans. In its ferrous form, it undergoes ligand release and doming upon photoexcitation, but its ferric form does not release the distal ligand, while the return to the ground state has been attributed to thermal relaxation. Here, by combining femtosecond Fe Kα and Kβ X-ray emission spectroscopy (XES) with Fe K-edge X-ray absorption near-edge structure (XANES), we demonstrate that the photocycle of ferric Cyt c is entirely due to a cascade among excited spin states of the iron ion, causing the ferric heme to undergo doming, which we identify. We also argue that this pattern is common to a wide diversity of ferric heme proteins, raising the question of the biological relevance of doming in such proteins.
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肌红蛋白在低温下重组。
DOI：
--
发表时间：
1987
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Chance,MR;Campbell,BF;Hoover,R;Friedman,JM
通讯作者：
Friedman,JM
影响因子：
15
作者：
Maes, EM;Walker, FA;Czernuszewicz, RS
通讯作者：
Czernuszewicz, RS
硝基蛋白 4 的超高分辨率结构中配体诱导的血红素褶皱和弯曲无几何形状。
影响因子：
2.9
作者：
Roberts,SA;Weichsel,A;Qiu,Y;Shelnutt,JA;Walker,FA;Montfort,WR
通讯作者：
Montfort,WR
影响因子：
2.9
作者：
Belikova, NA;Vladimirov, YA;Kagan, VE
通讯作者：
Kagan, VE
DOI：
10.1126/science.aam6203
发表时间：
2017-06-23
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Mara MW;Hadt RG;Reinhard ME;Kroll T;Lim H;Hartsock RW;Alonso-Mori R;Chollet M;Glownia JM;Nelson S;Sokaras D;Kunnus K;Hodgson KO;Hedman B;Bergmann U;Gaffney KJ;Solomon EI
通讯作者：
Solomon EI