A Marcus-Type Inverted Region in the Translocation Kinetics of a Knotted Protein
A Marcus-Type Inverted Region in the Translocation Kinetics of a Knotted Protein
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打结蛋白易位动力学中的马库斯型反向区域
DOI：
10.1021/acs.jpclett.3c02183
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Wanunu, Meni
中科院分区：
文献类型：
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作者：
Tripathi, Prabhat;Mehrafrooz, Behzad;Aksimentiev, Aleksei;Jackson, Sophie E.;Gruebele, Martin;Wanunu, Meni
结蛋白是一种罕见但重要的物种，但其复杂的拓扑结构如何影响其物理性质尚不完全清楚。在这里，我们将单分子纳米孔实验和全原子MD模拟相结合，研究了在转运过程中电场驱动的展开，通过单个蛋白质结的模型孔，对甲基化tRNA很重要。其中一个结表现出一种不寻常的行为，类似于电子在两个电位表面之间跳跃的行为：随着驱动易位反应的电势增加，速率最终趋于平稳或在“马库斯倒转状态”中减慢。我们的研究结果揭示了结蛋白的拓扑结构对其通过连接两个静电势阱的孔强制移位的影响。
Knotted proteins are rare but important species, yet how their complex topologies affect their physical properties is not fully understood. Here we combine single molecule nanopore experiments and all-atom MD simulations to study the electric-field-driven unfolding during the translocation through a model pore of individual protein knots important for methylating tRNA. One of these knots shows an unusual behavior that resembles the behavior of electrons hopping between two potential surfaces: as the electric potential driving the translocation reaction is increased, the rate eventually plateaus or slows back down in the “Marcus inverted regime”. Our results shed light on the influence of topology in knotted proteins on their forced translocation through a pore connecting two electrostatic potential wells.