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+.