Lectins in Precipitin Reactions with Soluble H Substance of Human Saliva and Serum

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Science  03 Aug 1973:
Vol. 181, Issue 4098, pp. 461-463
DOI: 10.1126/science.181.4098.461


Lectins that precipitate the soluble H substances of saliva were produced for the first time from the four commonly used sources of seed. In Ouchterlony precipitin reactions, identity was observed between extracts of Cytisus sessilifolius and Laburnum alpinum, but these extracts displayed incomplete identity with extracts from Ulex europaeus. These three sources of the precipitating lectin formed bands when tested with saliva from all secretors and none with saliva from nonsecretors. Extracts from Lotus tetragonolobus, however, formed two bands with saliva from secretors and one strong band with all saliva from nonsecretors. This new antigen, which reacts with Lotus, is present in all saliva and on red cells of all normal individuals, but it is absent in the Oh (Bombay) type. The lectins formed bands with serums of secretor and nonsecretor individuals, but these bands were weaker than those with saliva, and revealed incomplete identity between H substance of serum and saliva. The precipitin reaction of the lectins is an efficient method for demonstrating relations among lectins and among antigens and has led to the discovery of a new human antigen.