Current Blockades of Proteins Inside Nanopores for Real-Time Metabolome Analysis

Sarah Zernia, Nieck Jordi van der Heide, Nicole Stéphanie Galenkamp, Giorgos Gouridis, Giovanni Maglia*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

9 Citations (Scopus)
78 Downloads (Pure)

Abstract

Biological nanopores are emerging as powerful and low-cost sensors for real-time analysis of biological samples. Proteins can be incorporated inside the nanopore, and ligand binding to the protein adaptor yields changes in nanopore conductance. In order to understand the origin of these conductance changes and develop sensors for detecting metabolites, we tested the signal originating from 13 different protein adaptors. We found that the quality of the protein signal depended on both the size and charge of the protein. The engineering of a dipole within the surface of the adaptor reduced the current noise by slowing the protein dynamics within the nanopore. Further, the charge of the ligand and the induced conformational changes of the adaptor defined the conductance changes upon metabolite binding, suggesting that the protein resides in an electrokinetic minimum within the nanopore, the position of which is altered by the ligand. These results represent an important step toward understanding the dynamics of the electrophoretic trapping of proteins inside nanopores and will allow developing next-generation sensors for metabolome analysis.

Original languageEnglish
Article numberacsnano.9b09434
Pages (from-to)2296-2307
Number of pages12
JournalAcs Nano
Volume14
Issue number2
Early online date31-Jan-2020
DOIs
Publication statusPublished - Mar-2020

Keywords

  • nanopore
  • cytolysin A
  • metabolite sensor
  • substrate-binding protein
  • electrochemistry

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