Studies on a hemagglutinin from the mushroom Agaricus campestris.

A phytohemagglutinin has been isolated in 80 to 90% purity from the mushroom Agaricus campestris. This protein had a sedimentation constant of 4.2 S and an electrophoretic mobility, at pH 8.6, remindful of the properties of a fast y-globulin. It was a nonspecific agglutinin reacting with erythrocytes and leukocytes from a number of species. The hemagglutination reaction was independent of temperature from O-SO” and of pH from 4 to 10, but was ionic strength dependent. The hemagglutination reaction was not inhibited by sugars but was inhibited by a red cell ghost sonic suspension. Enzymatic and chemical treatments of the sonically disintegrated inhibitor indicated that part or all of the inhibitor was a protein or polypeptide.