Tachyplesin, a class of antimicrobial peptide from the hemocytes of the horseshoe crab (Tachypleus tridentatus). Isolation and chemical structure

• Published in: The Journal of biological chemistry Vol. 263; no. 32; pp. 16709 - 16713
• Main Authors: Nakamura, T, Furunaka, H, Miyata, T, Tokunaga, F, Muta, T, Iwanaga, S, Niwa, M, Takao, T, Shimonishi, Y
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 15.11.1988; American Society for Biochemistry and Molecular Biology
• Subjects: Amino Acid Sequence; Amino Acids - analysis; Aminoacids, peptides. Hormones. Neuropeptides; Analytical, structural and metabolic biochemistry; Animals; Anti-Bacterial Agents - analysis; Anti-Bacterial Agents - isolation & purification; Antimicrobial Cationic Peptides; Biological and medical sciences; Blood Cells - analysis; Brachyura - analysis; DNA-Binding Proteins; Fundamental and applied biological sciences. Psychology; Gram-Negative Bacteria - drug effects; Gram-Positive Bacteria - drug effects; Hemocytes - analysis; Immunodiffusion; Mass Spectrometry; Microbial Sensitivity Tests; Molecular Sequence Data; peptides; Peptides - analysis; Peptides - isolation & purification; Peptides, Cyclic; Proteins; tachyplesin; Tachypleus tridentatus; Hemocyte; Edman degradation; Coagulation; Hemolymph; Primary structure; Inhibition; Mass spectrometry; Aminoacid sequence
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(18)37448-9

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.