Properties of a Lectin in Chum Salmon Ova

A saline extract of chum salmon Oncorhynchus keta ova agglutinated rabbit erythrocytes but not human type B cells or sheep erythrocytes, and the hemagglutinating activity was independent of divalent cations. L-Rhamnose was the most effective inhibitor of a chum salmon ova lectin. Melibiose, L-arabinose, and D-galactose also inhibited the agglutination to some extent. The lectin was purified by affinity chromatography on L-rhamnose-Sepharose 6B and fast protein liquid chromatography on a Superose 12 column. The purified elctin showed a single band with a molecular weight of 22,000 in SDS-polyacrylamide gel electrophoresis with and without 2-mercaptoethanol. The agglutinin activity varied with the stages of development. The activity reduced markedly after the eyed stage and disappeared just before hatching. The purified lectin did agglutinate a fish pathogenic bacterium Vibrio anguillarum, but did not show the growth inhibition of bacterium.