1. Academic Validation
  2. Aromatic-rich C-terminal region of LCI is a potent antimicrobial peptide in itself

Aromatic-rich C-terminal region of LCI is a potent antimicrobial peptide in itself

  • Biochem Biophys Res Commun. 2019 Nov 5;519(2):372-377. doi: 10.1016/j.bbrc.2019.09.013.
Karabi Saikia 1 Vinay Kumar Belwal 1 Debika Datta 1 Nitin Chaudhary 2
Affiliations

Affiliations

  • 1 Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781 039, India.
  • 2 Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781 039, India. Electronic address: chaudhary@iitg.ac.in.
Abstract

LCI is a 47-residue antimicrobial peptide produced by Bacillus subtilis. The peptide displays potent activity against plant pathogens, Xanthomonas and Pseudomonas. The peptide takes a compact 3-dimensional structure characterized by a four-stranded β-sheet. The peptide is unusually rich in aromatic residues; 10 of the 47 residues are aromatic and 8 of them lie in the C-terminal region, LCI22-47. Here we report the antimicrobial activity of this C-terminal region against Gram-positive and Gram-negative bacteria. The C-terminal-amidated peptide displays potent activity against E. coli, methicillin and gentamicin-resistant S. aureus, and Xanthomonas oryzae pv. oryzae with lethal concentrations ≤4 μM. Membrane-binding assays indicate preferential binding to the negatively-charged lipids. The peptide permeabilizes the outer-membrane of E. coli indicating membrane-permeabilization as one of the mechanisms of killing. Interestingly, however, no inner-membrane permeabilization was observed, indicating that the membrane-permeabilization may not be the sole mechanism of action.

Keywords

Antimicrobial; Fluorescence; LCI(22-47); Membrane; Peptide.

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