RRC ID 52095
Author Taniguchi M, Ochiai A, Toyoda R, Sato T, Saitoh E, Kato T, Tanaka T.
Title Effects of arginine and leucine substitutions on anti-endotoxic activities and mechanisms of action of cationic and amphipathic antimicrobial octadecapeptide from rice α-amylase.
Journal J Pept Sci
Abstract Previously, we showed that the antimicrobial cationic and amphipathic octadecapeptide AmyI-1-18 from rice α-amylase (AmyI-1) inhibited the endotoxic activity of lipopolysaccharide (LPS) from Escherichia coli. In addition, we demonstrated that several AmyI-1-18 analogs containing arginine or leucine substitutions, which were designed on the basis of the helical wheel projection of AmyI-1-18, exhibited higher antimicrobial activity against human pathogenic microorganisms than AmyI-1-18. In the present study, anti-inflammatory (anti-endotoxic) activities of five AmyI-1-18 analogs containing arginine or leucine substitutions were investigated. Two single arginine-substituted and two single leucine-substituted AmyI-1-18 analogs inhibited the production of LPS-induced nitric oxide in mouse macrophages (RAW264) more effectively than AmyI-1-18. These data indicate that enhanced cationic and hydrophobic properties of AmyI-1-18 are associated with improved anti-endotoxic activity. In subsequent chromogenic Limulus amebocyte lysate assays, 50% inhibitory concentrations (IC50 ) of the three AmyI-1-18 analogs (G12R, D15R, and E9L) were 0.11-0.13 μm, indicating higher anti-endotoxic activity than that of AmyI-1-18 (IC50, 0.22 μm), and specific LPS binding activity. In agreement, surface plasmon resonance analyses confirmed direct LPS binding of three AmyI-1-18 analogs. In addition, AmyI-1-18 analogs exhibited little or no cytotoxic activity against RAW264 cells, indicating that enhancements of anti-inflammatory and LPS-neutralizing activities following replacement of arginine or leucine did not result in significant increases in cytotoxicity. This study shows that the arginine-substituted and leucine-substituted AmyI-1-18 analogs with improved anti-endotoxic and antimicrobial activities have clinical potential as dual-function host defense agents. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.
Volume 23(3)
Pages 252-260
Published 2017-3
DOI 10.1002/psc.2983
PMID 28185358
MeSH Amino Acid Sequence Amino Acid Substitution Animals Anti-Inflammatory Agents, Non-Steroidal / chemical synthesis Anti-Inflammatory Agents, Non-Steroidal / chemistry Anti-Inflammatory Agents, Non-Steroidal / pharmacology* Antimicrobial Cationic Peptides / chemical synthesis Antimicrobial Cationic Peptides / chemistry Antimicrobial Cationic Peptides / pharmacology* Arginine / chemistry* Cell Line Humans Hydrophobic and Hydrophilic Interactions Leucine / chemistry* Limulus Test Lipopolysaccharides / antagonists & inhibitors* Lipopolysaccharides / chemistry Lipopolysaccharides / pharmacology Macrophages / cytology Macrophages / drug effects Macrophages / metabolism Mice Nitric Oxide / antagonists & inhibitors Nitric Oxide / biosynthesis Oryza / chemistry Plant Proteins / chemical synthesis Plant Proteins / chemistry Plant Proteins / pharmacology* Protein Binding Structure-Activity Relationship alpha-Amylases / chemical synthesis alpha-Amylases / chemistry alpha-Amylases / pharmacology*
IF 1.969
Times Cited 7
Human and Animal Cells RAW 264(RCB0535)