Primary structure of anti-lipopolysaccharide factor from american horseshoe crab, Limulus polyphemus

Tatsushi Muta, Toshiyuki Miyata, Fuminori Tokunaga, Takanori Nakamura, Sadaaki Iwanaga

Research output: Contribution to journalArticlepeer-review

80 Citations (Scopus)


The complete amino acid sequence of anti-lipopolysaccharide (LPS) factor purified from the hemocytes lysate of the American horseshoe crab, Limulus polyphemus, was determined by characterization of the NH2-terminal sequence and the peptides generated after digestion of the protein with lysyl endopeptidase, clostripain, and Staphylococcus aureus V8 protease. Upon sequencing the peptides by the automated Edman method, the following primary structure was obtained:--S-S--. DGIWTQLIFTL. VKNNLATLWQSGDFQDHECHYRIKPTFRRLKWKYKGKFWCP. SWTSITGRATKSSRSGAVEHSVRNFVGQAKSSGLITQRQAEQFISQYN. During the sequence analysis, two species of the protein, which differed from each other at one locus, were found and characterized. L. polyphemus anti-LPS factor was a basic protein consisting of a single polypeptide chain of 101 residues and a calculated molecular weight of 11,786 or 11,800. The hydrophobic NH2-terminal sequence and the clustering of positive charges found in the disulfied loop yielded a typical amphipathic character of this protein. Moreover, L. polyphemus anti-LPS factor showed 83% sequence identity with the Tachypleus tridentatus protein, and the sequence similar to that observed in the EF-hand structure was found to contain in the COOH terminal portions of these proteins, although its function iss unknown.

Original languageEnglish
Pages (from-to)1321-1330
Number of pages10
JournalJournal of biochemistry
Issue number6
Publication statusPublished - 1987
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology


Dive into the research topics of 'Primary structure of anti-lipopolysaccharide factor from american horseshoe crab, Limulus polyphemus'. Together they form a unique fingerprint.

Cite this