Comparative study of lectin activity of higher basidiomycetes

Lectin activity of extracts from medicinal and edible mushrooms fruiting bodies (13 species) as well as from mycelia grown on liquid (6 species, 9 strains), and malt extract agar (11 species, 23 strains) media was evaluated for the first time using a hemagglutination (HA) with rabbit erythrocytes. It has been proved that the capability to synthesize lectins is widespread among higher Basidiomycetes, and HA activity is not only species- but also strain-dependent. Tremendous lectin HA titer was revealed in fruiting body extracts from Agaricus pilatianus and Coprinus comatus and comparatively high HA activity was revealed in Cerrena unicolor and Ganoderma ramnosissimum mycelial biomass. G. ramnosissimum strain 162 showed the highest among all fungi tested specifically for HA activity (64512 U/mg). The HA activity of extracts was inhibited with a large variety of carbohydrates. Lactose was the most potent inhibitor of fruiting body extracts from Agaricus pilatianus, Corpinus comatus, C. micaceus, Macrolepiota rachodes, and Tricholoma fractum, while lectins from Amanita ovoidea, Lepista nuda, and Melanoleuca brevipes exerted the highest specificity for galactose. Glucose appeared to be an exceptionally potent inhibitor of HA activity of fruiting body extracts from Leucoagaricus leucothitus with a minimal inhibition concentration of 0.39 mM. Lactose inhibited lectin activity of Coprinus comatus at a concentration of 0.78 mM while a much higher concentration of the same sugar (12.5 mM) was needed to prevent HA by fruiting body ex-tracts from C. micaceus. Liquid culture mycelia extracts from Cerrena unicolor and Trametes versicolor were galactose specific while Ganoderma lucidum and G. ramnosissmum showed specificity for arabinose and GlcNAc, respectively.