title: BT-benzo-29 inhibits bacterial cell proliferation by perturbing FtsZ assembly.
abstract: We have identified a potent antibacterial agent N-(4-sec-butylphenyl)-2-(thiophen-2-yl)-1H-benzo[d]imidazole-4-carboxamide (BT-benzo-29) from a library of benzimidazole derivatives that stalled bacterial division by inhibiting FtsZ assembly. A short (5 min) exposure of BT-benzo-29 disassembled the cytokinetic Z-ring in Bacillus subtilis cells without affecting the cell length and nucleoids. BT-benzo-29 also perturbed the localization of early and late division proteins such as FtsA, ZapA and SepF at the mid-cell. Further, BT-benzo-29 bound to FtsZ with a dissociation constant of 24 ± 3 μm and inhibited the assembly and GTPase activity of purified FtsZ. A docking analysis suggested that BT-benzo-29 may bind to FtsZ at the C-terminal domain near the T7 loop. BT-benzo-29 displayed significantly weaker inhibitory effects on the assembly and GTPase activity of two mutants (L272A and V275A) of FtsZ supporting the prediction of the docking analysis. Further, BT-benzo-29 did not appear to inhibit DNA duplication and nucleoid segregation and it did not perturb the membrane potential of B. subtilis cells. The results suggested that BT-benzo-29 exerts its potent antibacterial activity by inhibiting FtsZ assembly. Interestingly, BT-benzo-29 did not affect the membrane integrity of mammalian red blood cells. BT-benzo-29 bound to tubulin with a much weaker affinity than FtsZ and exerted significantly weaker effects on mammalian cells than on the bacterial cells indicating that the compound may have a strong antibacterial potential.
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India.
authors.forename: Shashikant
authors.initials: S
authors.lastname: Ray
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India.
authors.forename: Bhavya
authors.initials: B
authors.lastname: Jindal
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India.
authors.forename: Kishore
authors.initials: K
authors.lastname: Kunal
authors.affiliation: Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India.
authors.forename: Avadhesha
authors.initials: A
authors.lastname: Surolia
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India.
authors.forename: Dulal
authors.initials: D
authors.lastname: Panda
mesh_terms: D019943:Amino Acid Substitution; D000900:Anti-Bacterial Agents / Q000009:adverse effects / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001562:Benzimidazoles / Q000009:adverse effects / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D001665:Binding Sites; D018797:Cell Cycle Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D003598:Cytoskeletal Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D003599:Cytoskeleton / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D030562:Databases, Protein; D055808:Drug Discovery; D004912:Erythrocytes / Q000187:drug effects; D006367:HeLa Cells; D006801:Humans; D046529:Microscopy, Electron, Transmission; D008958:Models, Molecular; D008968:Molecular Conformation; D062105:Molecular Docking Simulation; D050505:Mutant Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D054852:Small Molecule Libraries; D013876:Thiophenes / Q000009:adverse effects / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001562:Benzimidazoles; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; C065103:FtsA protein, Bacteria; C071525:FtsZ protein, Bacteria; D050505:Mutant Proteins; C000604317:N-(4-sec-butylphenyl)-2-(thiophen-2-yl)-1H-benzo(d)imidazole-4-carboxamide; D011993:Recombinant Fusion Proteins; D054852:Small Molecule Libraries; D013876:Thiophenes
keywords: bacterial cell division; cytokinesis; fluorescence; membrane integrity; membrane potential