Novel compounds that specifically bind and modulate MscL: insights into channel gating mechanisms

FASEB J. 2019 Mar;33(3):3180-3189. doi: 10.1096/fj.201801628R. Epub 2018 Oct 25.


The bacterial mechanosensitive channel of large conductance (MscL) normally functions as an emergency release valve discharging cytoplasmic solutes upon osmotic stress. Opening the large pore of MscL inappropriately is detrimental to the cell, and thus it has been speculated to be a potential antibiotic target. Although MscL is one of the best studied mechanosensitive channels, no chemical that influenced bacterial growth by modulating MscL is known. We therefore used a high-throughput screen to identify compounds that slowed growth in an MscL-dependent manner. We characterized 2 novel sulfonamide compounds identified in the screen. We demonstrated that, although both increase MscL gating, one of these compounds does not work through the folate pathway, as other antimicrobial sulfonamides; indeed, the sulfonamide portion of the compound is not needed for activity. The only mode of action appears to be MscL activation. The binding pocket is where an α-helix runs along the cytoplasmic membrane and interacts with a neighboring subunit; analogous motifs have been observed in several prokaryotic and eukaryotic channels. The data not only demonstrate that MscL is a viable antibiotic target, but also give insight into the gating mechanisms of MscL, and they may have implications for developing agonists for other channels.-Wray, R., Iscla, I., Kovacs, Z., Wang, J., Blount, P. Novel compounds that specifically bind and modulate MscL: insights into channel gating mechanisms.

Keywords: antibiotic; mechanosensitive; osmoregulation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology
  • Binding Sites / genetics
  • Escherichia coli / drug effects
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Escherichia coli Proteins / drug effects*
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism*
  • High-Throughput Screening Assays
  • Ion Channel Gating / drug effects
  • Ion Channel Gating / physiology
  • Ion Channels / drug effects*
  • Ion Channels / genetics
  • Ion Channels / metabolism*
  • Mechanotransduction, Cellular / drug effects
  • Mechanotransduction, Cellular / physiology
  • Microbial Sensitivity Tests
  • Molecular Docking Simulation
  • Molecular Dynamics Simulation
  • Mutation
  • Sequence Homology, Amino Acid
  • Sulfonamides / chemistry
  • Sulfonamides / pharmacology


  • Anti-Bacterial Agents
  • Escherichia coli Proteins
  • Ion Channels
  • MscL protein, E coli
  • Sulfonamides