Production, purification, and characterization of Neurospora sitophila lectin.

Abstract

Neurospora sitophila produced extracellular and cell wall-associated lectins. The addition of l-sorbose to a culture resulted in a decrease in the production of the former lectin and complete abolition of the latter. The lectin in the culture filtrate was purified by bovine submaxillary mucin-conjugated Sepharose chromatography. The molecular weight of the lectin was calculated to be approx. 40,000 by Sephacryl S-200 gel filtration, and that of the subunit to be approx. 22,000 by SDS/polyacrylamide- gel electrophoresis. The lectin was not inhibited by simple sugars or their homopolymers. It was inhibited strongly by glycoproteins from human erythrocyte membrane and bovine submaxillary mucin, and moderately by α1-acid glycoprotein from human plasma, human IgA and IgM, and fetal calf fetuin. The lectin agglutinated human type A, B and O erythrocytes to the same degree. Erythrocytes from chick, horse, rabbit and sheep were more efficiently agglutinated.