Purification of a lectin from fruit bodies of Lactarius pergamenus (Fr.) Fr. and studies of its properties.

A lectin was purified from fruit bodies of the milk mushroom Lactarius pergamenus (Fr.) Fr. by a combination of ethanol precipitation, affinity chromatography on copolymer of polyvinyl alcohol and human blood B-group-specific substance, and ion-exchange chromatography on DEAE-Toyopearl. The lectin yield was 3 mg/kg of fresh mushrooms. Considerable loss of primary activity was observed during its purification, which, presumably, could be explained by disintegration of the lectin molecule, which consisted of six subunits, first to two molecules of three subunits, and then to individual subunits. There was a reverse tendency to aggregation during concentration of lectin solutions. Similar processes can take place in nature because of considerable individual variations of the lectin activity during growth of mushroom fruit bodies. The lectin weakly interacts with DGalNAc, while DGalβ1-3DGalNAc and DGalβ1-3DGlcNAc are the most probable candidates for ligands, with which the L. pergamenus lectin interacts at disaccharides level. The purified lectin may find application in histochemical research.