Nanosecond heme-to-heme electron transfer rates in a multiheme cytochrome nanowire reported by a spectrally unique His/Met-ligated heme.
Nanosecond heme-to-heme electron transfer rates in a multiheme cytochrome nanowire reported by a spectrally unique His/Met-ligated heme.
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DOI：
10.1073/pnas.2107939118
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发表时间：
2021-09-28
影响因子：
11.1
通讯作者：
Butt JN
中科院分区：
文献类型：
--
作者：
van Wonderen JH;Adamczyk K;Wu X;Jiang X;Piper SEH;Hall CR;Edwards MJ;Clarke TA;Zhang H;Jeuken LJC;Sazanovich IV;Towrie M;Blumberger J;Meech SR;Butt JN
多血红素细胞色素已被确定为细菌酶和细胞外氧化还原底物之间的电子交换所必需的蛋白质。在微生物学中，这些蛋白质有助于有效的能量储存和转换。在生物技术方面，多血红素细胞色素有助于生产绿色燃料和电力。此外，这些蛋白质还启发了分子级电子设备的设计。在这里，我们报告了在多个血红素细胞色素中异常高的血红素到血红素电子转移的比率。我们预计，在其他多血红素细胞色素中，尽管氨基酸序列和蛋白质折叠非常不同，但也有类似的高比率，这是生物学中报道的基态电子转移的最高比率之一，因为紧密堆积的血红素采用类似的配置。蛋白质通过一系列氧化还原辅因子的电子转移实现高效的能量储存和转换。多血红素细胞色素就是值得注意的例子。这些蛋白质在几个纳米的距离范围内将电子转移到>；10μm，在这样做的过程中，它们将细胞代谢与包括电极在内的细胞外氧化还原伙伴结合在一起。在这里，我们报告了泵浦-探测光谱学，它提供了这类令人着迷的蛋白质中血红素-血红素电子转移的内在速率的直接测量。我们的研究利用了一种光谱上独特的组氨酸/甲硫氨酸连接的血红素，该血红素被引入到第一希瓦氏菌胞外十氢血红素细胞外MtrC蛋白的特定位置。我们观察到血红素到血红素的电子转移速率约为109万S−1(边到边的距离)，与基于密度泛函和分子动力学计算的预测很好地一致。这些速率是生物学中报道的基态电子转移的最高速率之一。然而，有些比莫泽-达顿标尺低2到3个数量级，因为在这些短距离上的电子转移是通过空间进行的，因此与通常在较长距离上通过蛋白质隧道的情况相比，与更高的隧道势垒有关。此外，我们还证明了His/Met连接的血红素在100-μ的S时间尺度上创建了一个稳定电荷分离态的电子宿。这一特征可以在未来的多血红素细胞色素的设计中作为多功能光合作用生物杂交组件的组成部分加以利用。
Multiheme cytochromes have been identified as essential proteins for electron exchange between bacterial enzymes and redox substrates outside of the cell. In microbiology, these proteins contribute to efficient energy storage and conversion. For biotechnology, multiheme cytochromes contribute to the production of green fuels and electricity. Furthermore, these proteins inspire the design of molecular-scale electronic devices. Here, we report exceptionally high rates of heme-to-heme electron transfer in a multiheme cytochrome. We expect similarly high rates, among the highest reported for ground-state electron transfer in biology, in other multiheme cytochromes as the close-packed hemes adopt similar configurations despite very different amino acid sequences and protein folds. Proteins achieve efficient energy storage and conversion through electron transfer along a series of redox cofactors. Multiheme cytochromes are notable examples. These proteins transfer electrons over distance scales of several nanometers to >10 μm and in so doing they couple cellular metabolism with extracellular redox partners including electrodes. Here, we report pump-probe spectroscopy that provides a direct measure of the intrinsic rates of heme–heme electron transfer in this fascinating class of proteins. Our study took advantage of a spectrally unique His/Met-ligated heme introduced at a defined site within the decaheme extracellular MtrC protein of Shewanella oneidensis. We observed rates of heme-to-heme electron transfer on the order of 109 s−1 (3.7 to 4.3 Å edge-to-edge distance), in good agreement with predictions based on density functional and molecular dynamics calculations. These rates are among the highest reported for ground-state electron transfer in biology. Yet, some fall 2 to 3 orders of magnitude below the Moser–Dutton ruler because electron transfer at these short distances is through space and therefore associated with a higher tunneling barrier than the through-protein tunneling scenario that is usual at longer distances. Moreover, we show that the His/Met-ligated heme creates an electron sink that stabilizes the charge separated state on the 100-μs time scale. This feature could be exploited in future designs of multiheme cytochromes as components of versatile photosynthetic biohybrid assemblies.
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影响因子：
4.4
作者：
BERATAN, DN;ONUCHIC, JN;HOPFIELD, JJ
通讯作者：
HOPFIELD, JJ
DOI：
10.1021/acs.jpclett.0c02686
发表时间：
2020-11-19
期刊：
The journal of physical chemistry letters
影响因子：
--
作者：
Futera Z;Ide I;Kayser B;Garg K;Jiang X;van Wonderen JH;Butt JN;Ishii H;Pecht I;Sheves M;Cahen D;Blumberger J
通讯作者：
Blumberger J
影响因子：
4.6
作者：
Edwards MJ;White GF;Norman M;Tome-Fernandez A;Ainsworth E;Shi L;Fredrickson JK;Zachara JM;Butt JN;Richardson DJ;Clarke TA
通讯作者：
Clarke TA
DOI：
10.1073/pnas.1818003116
发表时间：
2019-02-26
影响因子：
11.1
作者：
Jiang, Xiuyun;Burger, Bastian;Blumberger, Jochen
通讯作者：
Blumberger, Jochen
影响因子：
56.9
作者：
BERATAN, DN;BETTS, JN;ONUCHIC, JN
通讯作者：
ONUCHIC, JN