气候变化领域集成服务门户(CCPortal): Electrical unfolding of cytochrome c during translocation through a nanopore constriction

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DOI	10.1073/pnas.2016262118
	Electrical unfolding of cytochrome c during translocation through a nanopore constriction
	Tripathi P.; Benabbas A.; Mehrafrooz B.; Yamazaki H.; Aksimentiev A.; Champion P.M.; Wanunu M.
发表日期	2021
ISSN	00278424
卷号	118 期号:17
英文摘要	Many small proteins move across cellular compartments through narrow pores. In order to thread a protein through a constriction, free energy must be overcome to either deform or completely unfold the protein. In principle, the diameter of the pore, along with the effective driving force for unfolding the protein, as well as its barrier to translocation, should be critical factors that govern whether the process proceeds via squeezing, unfolding/threading, or both. To probe this for a well-established protein system, we studied the electric-field–driven translocation behavior of cytochrome c (cyt c) through ultrathin silicon nitride (SiNx) solid-state nanopores of diameters ranging from 1.5 to 5.5 nm. For a 2.5-nm-diameter pore, we find that, in a threshold electric-field regime of ∼30 to 100 MV/m, cyt c is able to squeeze through the pore. As electric fields inside the pore are increased, the unfolded state of cyt c is thermodynamically stabilized, facilitating its translocation. In contrast, for 1.5- and 2.0-nm-diameter pores, translocation occurs only by threading of the fully unfolded protein after it transitions through a higher energy unfolding intermediate state at the mouth of the pore. The relative energies between the metastable, intermediate, and unfolded protein states are extracted using a simple thermodynamic model that is dictated by the relatively slow (∼ms) protein translocation times for passing through the nanopore. These experiments map the various modes of protein translocation through a constriction, which opens avenues for exploring protein folding structures, internal contacts, and electric-field–induced deformability. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Cytochrome c; Electric field unfolding; Nanopore biophysics; Protein folding; Solid-state nanopore
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/179776
作者单位	Department of Physics, Northeastern University, Boston, MA 02115, United States; Center for Biophysics and Quatitative Biology, University of Illinois at Urbana–Champaign, Urbana, IL 61801, United States; Department of Physics, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana–Champaign, Urbana, IL 61801, United States; Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, MA 02115, United States
推荐引用方式 GB/T 7714	Tripathi P.,Benabbas A.,Mehrafrooz B.,et al. Electrical unfolding of cytochrome c during translocation through a nanopore constriction[J],2021,118(17).
APA	Tripathi P..,Benabbas A..,Mehrafrooz B..,Yamazaki H..,Aksimentiev A..,...&Wanunu M..(2021).Electrical unfolding of cytochrome c during translocation through a nanopore constriction.Proceedings of the National Academy of Sciences of the United States of America,118(17).
MLA	Tripathi P.,et al."Electrical unfolding of cytochrome c during translocation through a nanopore constriction".Proceedings of the National Academy of Sciences of the United States of America 118.17(2021).