Volume 135, Issue 7 e202214566
Forschungsartikel

An Engineered OmpG Nanopore with Displayed Peptide Motifs for Single-Molecule Multiplex Protein Detection

Joshua C. Foster

Joshua C. Foster

Molecular and Cellular Biology Program, University of Massachusetts Amherst, Amherst, MA 01003 USA

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Bach Pham

Bach Pham

Department of Chemistry, University of Massachusetts Amherst, Amherst, MA 01003 USA

Current address: Department of Chemistry, University of Science, Vietnam National University, Hanoi, Vietnam

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Ryan Pham

Ryan Pham

Department of Chemistry, University of Massachusetts Amherst, Amherst, MA 01003 USA

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Minji Kim

Minji Kim

Department of Food Science, University of Massachusetts Amherst, Amherst, MA 01003 USA

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Prof. Matthew D. Moore

Prof. Matthew D. Moore

Molecular and Cellular Biology Program, University of Massachusetts Amherst, Amherst, MA 01003 USA

Department of Food Science, University of Massachusetts Amherst, Amherst, MA 01003 USA

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Prof. Min Chen

Corresponding Author

Prof. Min Chen

Molecular and Cellular Biology Program, University of Massachusetts Amherst, Amherst, MA 01003 USA

Department of Chemistry, University of Massachusetts Amherst, Amherst, MA 01003 USA

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First published: 01 December 2022

Abstract

Molecular detection via nanopore, achieved by monitoring changes in ionic current arising from analyte interaction with the sensor pore, is a promising technology for multiplex sensing development. Outer Membrane Protein G (OmpG), a monomeric porin possessing seven functionalizable loops, has been reported as an effective sensing platform for selective protein detection. Using flow cytometry to screen unfavorable constructs, we identified two OmpG nanopores with unique peptide motifs displayed in either loop 3 or 6, which also exhibited distinct analyte signals in single-channel current recordings. We exploited these motif-displaying loops concurrently to facilitate single-molecule multiplex protein detection in a mixture. We additionally report a strategy to increase sensor sensitivity via avidity motif display. These sensing schemes may be expanded to more sophisticated designs utilizing additional loops to increase multiplicity and sensitivity.

Conflict of interest

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

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