S. Murali et al., A LIPOPOLYSACCHARIDE-BINDING HEMAGGLUTININ WITH SPECIFICITY FOR ACETYLATED AMINOSUGARS IN THE SERUM OF THE HERMIT-CRAB DIOGENES AFFINIS (HENDERSON), Journal of invertebrate pathology, 64(3), 1994, pp. 221-227
A naturally occurring hemagglutinin was detected in the serum of the h
ermit crab Diogenes affinis, and its erythrocyte (RBC) binding activit
ies, physicochemical properties, and carbohydrate binding specificity
were characterized. Both the hemagglutination profile and the pattern
of crossreactivity of the serum with different RBC types in cross-adso
rption tests suggested a strong affinity of the serum agglutinin for r
at RBC. Further analysis revealed that the agglutinin was specifically
dependent on Ca2+ for its hemagglutinating activity and reversibly se
nsitive to EDTA. The activity was found to be stable between pH 6.0 an
d 7.5, heat-labile, and completely precipitable by ammonium sulphate o
r TCA, suggesting the proteinaceous nature of the serum agglutinin. In
hemagglutination-inhibition assays, the serum agglutinin of D. affini
s showed a distinct and unique specificity for acetyl group-containing
carbohydrates and glycoprotein. Furthermore, the hemagglutinating act
ivity of the serum agglutinin was also inhibited by lipopolysaccharide
from Salmonella abortus equi, which might indicate a significant role
of humoral agglutinin in the immune response of crustaceans against b
acterial infections. (C) 1994 Academic Press, Inc.