Biological Activities of Anti-LPS Factor and LPS Binding Peptide from Horseshoe Crab Amoebocytes
Amoebocytes of horseshoe crabs (such as Limulus polyphemus and Tachypleus tridentatus) contain a coagulation system which is triggered by minute amounts of endotoxic lipopolysaccharide (LPS) and (1–3)-β-D-glucan and result in gelation of hemolymph. Limulus amoebocyte lysate (LAL) is now widely employed as a sensitive assay method for endotoxin. Iwanaga et al. (7), purified reaction components of the gelation cascade and clarified the mechanism of the gelation reaction. In the course of their extensive studies Tanaka et al., (15) discovered a potent anticoagulant, named Anti-LPS Factor (ALF), which specifically inhibits the activation of Factor C by LPS. ALF is a simple basic protein with a molecular weight of 11,600 Da and the unique chemical structure of this protein was described in detail by Iwanaga et al., in this volume and elsewhere (1, 8). In collaborative studies we have found interesting biological activities of ALF such as hemolysis of LPS sensitized erythrocytes (12) and growth inhibition of Gram negative bacteria (10).
KeywordsMinimal Inhibitory Concentration Horseshoe Crab Lipid Moiety Precipitation Line Interesting Biological Activity
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