title: Electrostatic Interactions between OmpG Nanopore and Analyte Protein Surface Can Distinguish between Glycosylated Isoforms.
abstract: The flexible loops decorating the entrance of OmpG nanopore move dynamically during ionic current recording. The gating caused by these flexible loops changes when a target protein is bound. The gating is characterized by parameters including frequency, duration, and open-pore current, and these features combine to reveal the identity of a specific analyte protein. Here, we show that OmpG nanopore equipped with a biotin ligand can distinguish glycosylated and deglycosylated isoforms of avidin by their differences in surface charge. Our studies demonstrate that the direct interaction between the nanopore and analyte surface, induced by the electrostatic attraction between the two molecules, is essential for protein isoform detection. Our technique is remarkably sensitive to the analyte surface, which may provide a useful tool for glycoprotein profiling.
authors.affiliation: Molecular and Cellular Biology Program and Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States.
authors.forename: Monifa A
authors.initials: MA
authors.lastname: Fahie
authors.affiliation: Molecular and Cellular Biology Program and Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States.
authors.forename: Min
authors.initials: M
authors.lastname: Chen
mesh_terms: D001360:Avidin / Q000737:chemistry*; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry*; D001710:Biotin / Q000737:chemistry*; D029968:Escherichia coli Proteins / Q000737:chemistry*; D006031:Glycosylation; D006863:Hydrogen-Ion Concentration; D058608:Nanopores; D018272:Porins / Q000737:chemistry*; D011485:Protein Binding; D020033:Protein Isoforms / Q000737:chemistry; D055672:Static Electricity; D019809:Streptavidin / Q000737:chemistry; D013499:Surface Properties
chemical_list: D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; C114347:OmpG protein, E coli; D018272:Porins; D020033:Protein Isoforms; D001360:Avidin; D001710:Biotin; D019809:Streptavidin