Screening of a unique lectin from 16 cultivable mushrooms with hybrid glycoprotein and neoproteoglycan probes and purification of a novel N-acetylglucosamine-specific lectin from Oudemansiella platyphylla fruiting body

Hybrid glycoprotein and neoproteoglycan probes were prepared by coupling va rious glycoproteins or polysaccharides to peroxidase or biotinyl bovine ser um albumin, respectively. Lectins recognizable by the neoglycoconjugate pro bes were extracted from 16 cultivable mushrooms. Dot-blot assay revealed fi ve extracts to be reactive with only hybrid glycoprotein probes, but others also reacted with neoproteoglycan probes. According to the reactivity patt ern with probe screening, the one lectin from Oudemansiella platyphylla ext ract (OPL) bound best with asialotransferrin- and asialoagalactotransferrin -peroxidase probes and was isolated using an asialotransferrin column, but it did not bind with other hybrid glycoprotein or neoproteoglycan probes. O PL, consisting of two polypeptides with high homology in the N-terminal ami no acid sequences, exhibited weak hemagglutinating activity. Purified OPL s pecifically bound the beta -GlcNAc probe among various biotinylated polymer ic sugar probes, while it exhibited essentially the same binding specificit y toward neoglycoconjugate probes as that of the crude extract, showing a p reference for the asialobiantennary complex type of N-linked glycans. These results indicate that the neoglycoconjugate probes are valuable in lectin screening. (C) 2001 Elsevier Science B.V. All rights reserved.