A new marker for neuraminidase-treated human serum glycoproteins from the haemolymph of Tridacna maxima (Röding).

Highly purified human serum glycoproteins were treated with neuraminidase. The exposed subterminal carbohydrate structures reacted strongly with an anti-galactan precipitin from the haemolymph of Tridacna maxima which detects terminal, non-reducing beta-D-galactoside residues. This invertebrate precipitin, Tridacnin, may be used as a marker for nearly two thirds of all asialo serum glycoproteins; A number of different cross-reactions with various other polysaccharides and galactans subdivides those neuraminidase-treated glycoproteins into several subgroups, indicating that the uncovered carbohydrate structures are not always completely identical. In this way, together with the cross-reacting precipitins from plant and invertebrate origin. Tridacnin may be a useful tool for elucidating and establishing the structure of the carbohydrate part of serum glycoproteins.