Crystallization and characterization of a lectin obtained from a mushroom, Aleuria aurantia

A fucose-specific lectin with a unique sugar recognizing property was purified from an orange peel mushroom, Aleuria aurantia, by using a specific affinity adsorbent prepared from L-fucose and starch. From 100 g of fruiting bodies, 145 mg of pure lectin was obtained. The lectin was crystallized and the crystals showed hexagonal bipyramid in shape. Distribution of hydrophobic and hydrophilic regions in the molecule of this lectin was predicted from the amino acid sequence deduced from the previously reported nucleotide sequence of the lectin cDNA. Circular dichroism spectra revealed a very low content of alpha-helical and beta-sheet structures and a relatively high content of turns in this lectin. From the spectrum observed in the presence of L-fucose, a hapten sugar of this lectin, certain conformational change was assumed to occur.