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Title: Alarin but not its alternative-splicing form, GALP (Galanin-like peptide) has antimicrobial activity

Highlights: • Alarin inhibits the growth of E. coli but not S. aureus. • Alarin’s potency is comparable to LL-37 in inhibiting the growth of E. coli. • Alarin can cause bacterial membrane blebbing. • Alalin does not induce hemolysis on erythrocytes. -- Abstract: Alarin is an alternative-splicing form of GALP (galanin-like peptide). It shares only 5 conserved amino acids at the N-terminal region with GALP which is involved in a diverse range of normal brain functions. This study seeks to investigate whether alarin has additional functions due to its differences from GALP. Here, we have shown using a radial diffusion assay that alarin but not GALP inhibited the growth of Escherichia coli (strain ML-35). The conserved N-terminal region, however, remained essential for the antimicrobial activity of alarin as truncated peptides showed reduced killing effect. Moreover, alarin inhibited the growth of E. coli in a similar potency as human cathelicidin LL-37, a well-studied antimicrobial peptide. Electron microscopy further showed that alarin induced bacterial membrane blebbing but unlike LL-37, it did not cause hemolysis of erythrocytes. In addition, alarin is only active against the gram-negative bacteria, E. coli but not the gram-positive bacteria, Staphylococcus aureus. Thus, these data suggest that alarinmore » has potentials as an antimicrobial and should be considered for the development in human therapeutics.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [7] ;  [8] ;  [9]
  1. Department of Bacteriology, Institute of Tropical Medicine, Nagasaki University, Nagasaki 8528523 (Japan)
  2. Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur (Malaysia)
  3. Department of Applied Biochemistry, Institute of Glycoscience, Tokai University, Kanagawa 2591292 (Japan)
  4. Department of Bioscience, Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, Shiga 5260829 (Japan)
  5. Electron Microscopy Shop Central Laboratory, Institute of Tropical Medicine, Nagasaki University, Nagasaki 8528523 (Japan)
  6. Institute Pedro Kouri, Havana (Cuba)
  7. Division of Cytokine Signaling, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 8528523 (Japan)
  8. Department of Pathology, Institute of Tropical Medicine, Nagasaki University, Nagasaki 8528523 (Japan)
  9. Kenya Research Station, Institute of Tropical Medicine, Nagasaki University, Nagasaki 8528523 (Japan)
Publication Date:
OSTI Identifier:
22239568
Resource Type:
Journal Article
Resource Relation:
Journal Name: Biochemical and Biophysical Research Communications; Journal Volume: 434; Journal Issue: 2; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; AMINO ACIDS; BRAIN; ELECTRON MICROSCOPY; ERYTHROCYTES; ESCHERICHIA COLI; HEMOLYSIS; PEPTIDES; SPLICING; STAPHYLOCOCCUS