LECTINS IN THE ROCK LOBSTER JASUS-NOVAEHOLLANDIAE HEMOLYMPH

Hemolymph of three different species of rock lobsters was examined for its agglutinating activity using mammalian erythrocytes and bacteria. The hemolymph of the red rock lobster Jasus novaehollandiae agglutina ted human ABO erythrocytes and a marine bacterium Pseudomonas aerugino sa. The hemagglutinating activity was, however, inconsistent, and vari ed from a titer of 4 to 1024 for human erythrocytes. J. novaehollandia e lectins were heat-labile and the hemagglutinating activity was depen dent on the presence of Ca2+. The major lectin named JN-2 was a glycop rotein having a molecular weight of 400,000 and dissociated into subun its of different molecular sizes (85, 81, and 63kD). Porcine stomach m ucin (PSM), asialo-PSM, and fetuin were effective inhibitors to J. nov aehollandiae lectins. N-acetylneuraminic acid did not inhibit the hema gglutinating activity. Simple sugars such as D-ribose, D-arabinose, an d D-galactose also inhibited the hemagglutinating activity to some ext ent. Another species of the red rock lobster J. edwardsii was found to possess lectins similar to those of J. novaehollandiae. On the contra ry, the humoral lectin(s) of the green rock lobster J. verreauxi was s ialic acid-specific, and the lectin activity was independent of the pr esence of Ca2+.