The hemolymph clottable proteins of tiger shrimp, Penaeus monodon, and related species

A clottable protein was purified from the hemolymph of tiger shrimp (Penaeu s monodon) by sequential DEAE anion-exchange chromatography. The protein fo rmed stable clots in the presence of Ca2+ and the transglutaminase in hemoc yte lysate. It is thermostable at temperatures up to 66 degrees C. The mole cular mass of the clottable protein was determined to be 380 kDa by SDS-PAG E and MALDI-TOF mass spectrometry, and the protein exists as disulfide-link ed homodimers and oligomers. The size and amino acid composition of the clo ttable protein are similar to those of several other shrimps, prawns, lobst er and crayfish, and their N-terminal amino acid sequences are 60-80% ident ical. Monosaccharide analysis of the clottable protein revealed the presenc e of mannose, glucosamine or N-acetylglucosamine and possibly glucose in th is glycoprotein of about 5% sugar content. Lipid in the protein upon electr ophoresis was hardly detectable with the Oil Red O staining method. In immu nodiffusion and immunoblotting analyses, the anti-clottable protein antibod ies reacted with the clottable proteins from the penaeid shrimps but not wi th those from other crustaceans. (C) 1998 Elsevier Science Inc. All rights reserved.