Tags: Protein.
Coagulin is a gel-forming protein of hemolymph that hinders the spread of invaders by immobilising them.The protein contains a single 175- residue polypeptide chain; this is cleaved after Arg-18 and Arg-46 by a clotting enzyme contained in the hemocyte and activated by a bacterial endotoxin (lipopolysaccharide). Cleavage releases two chains of coagulin A and B linked by two disulphide bonds together with the peptide C. Gel formation results from interlinking of coagulin molecules.