Real-Time Nanopore-Based Recognition of Protein Translocation Success.
Biophys J
; 114(4): 772-776, 2018 02 27.
Article
en En
| MEDLINE
| ID: mdl-29338842
ABSTRACT
A growing number of new technologies are supported by a single- or multi-nanopore architecture for capture, sensing, and delivery of polymeric biomolecules. Nanopore-based single-molecule DNA sequencing is the premier example. This method relies on the uniform linear charge density of DNA, so that each DNA strand is overwhelmingly likely to pass through the nanopore and across the separating membrane. For disordered peptides, folded proteins, or block copolymers with heterogeneous charge densities, by contrast, translocation is not assured, and additional strategies to monitor the progress of the polymer molecule through a nanopore are required. Here, we demonstrate a single-molecule method for direct, model-free, real-time monitoring of the translocation of a disordered, heterogeneously charged polypeptide through a nanopore. The crucial elements are two "selectivity tags"-regions of different but uniform charge density-at the ends of the polypeptide. These affect the selectivity of the nanopore differently and enable discrimination between polypeptide translocation and retraction. Our results demonstrate exquisite sensitivity of polypeptide translocation to applied transmembrane potential and prove the principle that nanopore selectivity reports on biopolymer substructure. We anticipate that the selectivity tag technique will be broadly applicable to nanopore-based protein detection, analysis, and separation technologies, and to the elucidation of protein translocation processes in normal cellular function and in disease.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Simulación por Computador
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Modelos Moleculares
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Canales Aniónicos Dependientes del Voltaje
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Nanoporos
Límite:
Humans
Idioma:
En
Revista:
Biophys J
Año:
2018
Tipo del documento:
Article