Global redesign of a native β-barrel scaffold

Aaron J. Wolfe, Mohammad M. Mohammad, Avinash K. Thakur, Liviu Movileanu

Research output: Contribution to journalArticle

12 Scopus citations

Abstract

One persistent challenge in membrane protein design is accomplishing extensive modifications of proteins without impairing their functionality. A truncation derivative of the ferric hydroxamate uptake component A (FhuA), which featured the deletion of the 160-residue cork domain and five large extracellular loops, produced the conversion of a non-conductive, monomeric, 22-stranded β-barrel protein into a large-conductance protein pore. Here, we show that this redesigned β-barrel protein tolerates an extensive alteration in the internal surface charge, encompassing 25 negative charge neutralizations. By using single-molecule electrophysiology, we noted that a commonality of various truncation FhuA protein pores was the occurrence of 33% blockades of the unitary current at very high transmembrane potentials. We determined that these current transitions were stimulated by their interaction with an external cationic polypeptide, which occurred in a fashion dependent on the surface charge of the pore interior as well as the polypeptide characteristics. This study shows promise for extensive engineering of a large monomeric β-barrel protein pore in molecular biomedical diagnosis, therapeutics, and biosensor technology.

Original languageEnglish (US)
Pages (from-to)19-29A
JournalBiochimica et Biophysica Acta - Biomembranes
Volume1858
Issue number1
DOIs
StatePublished - Jan 1 2016

Keywords

  • FhuA
  • Ion channel
  • Membrane protein engineering
  • Single-molecule electrophysiology
  • Spontaneous gating

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Cell Biology

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