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Updated: Aug 18, 2026

Blood Collection from the American Horseshoe Crab, Limulus Polyphemus
12:48

Blood Collection from the American Horseshoe Crab, Limulus Polyphemus

Published on: October 13, 2008

Proteinase inhibitory activity released from the horseshoe crab blood cell during exocytosis

P B Armstrong, J P Quigley

    Biochimica Et Biophysica Acta
    |March 1, 1985
    PubMed

    The blood cell of the horseshoe crab, Limulus, is packed with granules that can be stimulated to release their contents by exocytosis. We have identified a family of proteinase inhibitors in the released materials. Included is a factor similar to the alpha 2-macroglobulin homologue present in the plasma and acid-stable and acid-instable active-site inhibitors. The acid-stable factor is active against both serine (trypsin, chymotrypsin) and metal (thermolysin) proteinases. The trypsin- and chymotrypsin-inhibitory activity has a molecular weight of 6100, as determined by gel-filtration chromatography.

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