title: Tachyplesin, a class of antimicrobial peptide from the hemocytes of the horseshoe crab (Tachypleus tridentatus). Isolation and chemical structure.
abstract: A cationic peptide, designated tachyplesin, was isolated from acid extracts of horseshoe crab (Tachypleus tridentatus) hemocyte debris. It consists of 17 residues and the structure determined by Edman degradation is: (formula; see text) The carboxyl-terminal end of this peptide was identified as arginine alpha-amide, and the whole sequence including the alpha-amide was also confirmed by fast atom bombardment mass spectrometry, indicating a mass value of 2263. Tachyplesin inhibits growth of both Gram-negative and -positive bacteria at low concentrations and formed a complex with bacterial lipopolysaccharide. Tachyplesin seems likely to act as antimicrobial peptide for self-defense in the horseshoe crab against invading microorganisms.
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis / Q000302:isolation & purification*; D023181:Antimicrobial Cationic Peptides; D001773:Blood Cells / Q000032:analysis*; D003386:Brachyura / Q000032:analysis*; D004268:DNA-Binding Proteins; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006434:Hemocytes / Q000032:analysis*; D005779:Immunodiffusion; D013058:Mass Spectrometry; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010455:Peptides / Q000032:analysis / Q000302:isolation & purification*; D010456:Peptides, Cyclic
chemical_list: D000596:Amino Acids; D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D004268:DNA-Binding Proteins; D010455:Peptides; D010456:Peptides, Cyclic; C057636:tachyplesin peptide, Tachypleus tridentatus