title: Inhibitory effects of a novel cationic dodecapeptide [CL(14-25)] derived from cyanate lyase of rice on endotoxic activities of LPSs from Escherichia coli and periodontopathic Aggregatibacter actinomycetemcomitans.
abstract: OBJECTIVE
  CL(14-25), a dodecapeptide of cyanate lyase from rice, is a novel cationic α-helical antimicrobial peptide. In this study, we examined inhibitory ability of CL(14-25) against endotoxic activities of lipopolysaccharides (LPSs) from Escherichia coli and periodontal pathogenic Aggregatibacter actinomycetemcomitans.
  
  
  METHODS
  Endotoxin-neutralizing activity of CL(14-25) was evaluated by inhibition to induction of cytokine and nitric oxide in human aortic endothelial cells (HAECs) and RAW264 mouse macrophage cells, respectively. Protective effect of CL(14-25) was determined in mice against lethal toxicity of LPS.
  
  
  RESULTS
  IL-6 in HAECs was induced by stimulation with LPS preparations of A. actinomycetemcomitans and E. coli tested in this study, and addition of CL(14-25) to the medium caused inhibition of their induction in a dose-dependent manner. CL(14-25) inhibited NO induction in RAW264 cells by a smooth type LPS of E. coli O55:B5 and an Rc type LPS of E. coli J5 as well as lipid A of E. coli R515 in a dose-dependent manner. Simultaneous injection of E. coli O55:B5 LPS and CL(14-25) in BALB/c mice resulted in prevention of lethal toxicity of the former. The results of a Limulus amebocyte lysate assay and surface plasmon resonance analysis of interaction between CL(14-25) and E. coli LPS or lipid A showed that CL(14-25) specifically binds to a lipid A moiety of LPS.
  
  
  CONCLUSIONS
  The results of present study suggest that CL(14-25) has a potential to be used as a nutraceutical agent for periodontal therapy.
authors: Department of Periodontology, Tokyo Dental College, Tokyo 101-0061, Japan.
authors: Saori
authors: S
authors: Takayama
authors: Department of Materials Science and Technology, Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan.
authors: Kenji
authors: K
authors: Hashimoto
authors: Department of Microbiology, Tokyo Dental College, Tokyo 101-0061, Japan; Oral Health Science Center, Tokyo Dental College, Tokyo 101-0061, Japan.
authors: Eitoyo
authors: E
authors: Kokubu
authors: Department of Materials Science and Technology, Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan.
authors: Masayuki
authors: M
authors: Taniguchi
authors: Department of Materials Science and Technology, Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan.
authors: Kouji
authors: K
authors: Tajima
authors: Department of Materials Science and Technology, Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan.
authors: Akihito
authors: A
authors: Ochiai
authors: Graduate School of Technology, Niigata Institute of Technology, Niigata 945-1195, Japan.
authors: Eiichi
authors: E
authors: Saitoh
authors: Department of Periodontology, Tokyo Dental College, Tokyo 101-0061, Japan; Oral Health Science Center, Tokyo Dental College, Tokyo 101-0061, Japan.
authors: Atsushi
authors: A
authors: Saito
authors: Department of Microbiology, Tokyo Dental College, Tokyo 101-0061, Japan; Oral Health Science Center, Tokyo Dental College, Tokyo 101-0061, Japan.
authors: Kazuyuki
authors: K
authors: Ishihara
authors: Laboratory of Chemistry, Tokyo Dental College, Tokyo 101-0062, Japan. Electronic address: tekato@tdc.ac.jp.
authors: Tetsuo
authors: T
authors: Kato
mesh_terms: D016976:Aggregatibacter actinomycetemcomitans / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D019759:Carbon-Nitrogen Lyases / Q000737:chemistry*; D016207:Cytokines / Q000096:biosynthesis / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D042783:Endothelial Cells / Q000187:drug effects; D004926:Escherichia coli / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis; D008050:Lipid A / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000633:toxicity; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000633:toxicity; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009569:Nitric Oxide / Q000096:biosynthesis / Q000378:metabolism; D012275:Oryza / Q000201:enzymology; D010446:Peptide Fragments / Q000737:chemistry / Q000494:pharmacology*; D000067996:RAW 264.7 Cells
chemical_list: C000608016:CL(14-25); D016207:Cytokines; D015850:Interleukin-6; D008050:Lipid A; D008070:Lipopolysaccharides; D010446:Peptide Fragments; D009569:Nitric Oxide; C019953:cyanate hydrolase; D019759:Carbon-Nitrogen Lyases
keywords: Antimicrobial peptides; Inflammatory mediator; Lipopolysaccharide