Structure-Function Relationships of Tachyplesins and their Analogues

  1. Joan Marsh Organizer and
  2. Jamie A. Goode
  1. Sadaaki Iwanaga Faculty of Science1,2,
  2. Tatsushi Muta1,2,
  3. Takeshi Shigenaga2,
  4. Noriaki Seki2,
  5. Keiichi Kawano Faculty of Dentistry3,
  6. Takashi Katsu4 and
  7. Shun-Ichiro Kawabata1,2

Published Online: 28 SEP 2007

DOI: 10.1002/9780470514658.ch10

Ciba Foundation Symposium 186 - Antimicrobial Peptides

Ciba Foundation Symposium 186 - Antimicrobial Peptides

How to Cite

Iwanaga, S., Muta, T., Shigenaga, T., Seki, N., Kawano, K., Katsu, T. and Kawabata, S.-I. (2007) Structure-Function Relationships of Tachyplesins and their Analogues, in Ciba Foundation Symposium 186 - Antimicrobial Peptides (eds J. Marsh and J. A. Goode), John Wiley & Sons, Ltd., Chichester, UK. doi: 10.1002/9780470514658.ch10

Author Information

  1. 1

    Department of Molecular Biology, Graduate School of Medical Science, Kyushu University 33, Hakozaki, Fukuoka 812, Japan

  2. 2

    Department of Biology, Kyushu University 33, Hakozaki, Fukuoka 812, Japan

  3. 3

    Kyushu University 33, Fukuoka 812, Tsushima, Okayama 700, Japan

  4. 4

    Faculty of Pharmaceutical Sciences, Okayama University, Tsushima, Okayama 700, Japan

Publication History

  1. Published Online: 28 SEP 2007

ISBN Information

Print ISBN: 9780471950257

Online ISBN: 9780470514658

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Keywords:

  • structure-function relationships;
  • tachyplesins;
  • haemocytes;
  • escherichia coli;
  • candida albicans

Summary

Haemocytes of the horseshoe crab (Limulus) contain a new family of arthropodous peptide antibiotics, termed the tachyplesin family. These cationic peptides are composed of 17–18 amino acid residues with a C-terminal arginine α-amide. Tachyplesin I takes on a fairly rigid conformation constrained by two disulphide bridges and adopts a conformation consisting of an antiparallel β-sheet connected by a β-turn. Isopeptides of tachyplesin I with amino acid replacements, tachyplesins II and III, and polyphemusins I and II have also been found in the haemocytes of the South-East Asian species and Limulus polyphemus. These peptides are present in abundance in the small granules of the haemocytes and inhibit strongly the growth of not only Gram-negative and Gram-positive bacteria but also fungi such as Candida albicans. Tachyplesin exists in the prepro form consisting of 77 residues; this precursor is probably processed by intracellular proteases and an amidation enzyme before incorporation into the small granules of the haemocytes. We examined the mode of action of tachyplesin I on biomembranes, comparing it with that of gramicidin S. Tachyplesin caused an efflux of K+ from Staphylococcus aureus and Escherichia coli cells similar to that caused by gramicidin S. Another antimicrobial substance, anti-LPS factor, has been isolated from haemocytes.