Mannose-specific lectin from the mushroom Hygrophorus russula

Abstract

A lectin was purified from the mushroom Hygrophorus russula by affinity chromatography on a Sephadex G-50 column and BioAssist S cation exchange chromatography and designated H. russula lectin (HRL). The results of sodium dodecyl sulfate-polyaclylamidegel electrophoresis, gel filtration and matrix-assisted laser desorption ionization time-of-flight mass spectrometry of HRL indicated that it was composed of four identical 18.5 kDa subunits with no S-S linkage. Isoelectric focusing of the lectin showed bands near pI 6.40. The complete sequence of 175 amino acid residues was determined by amino acid sequencing of intact or enzyme-digested HRL. The sequence showed homology with Grifola frondosa lectin. The cDNA of HRL was cloned from RNA extracted from the mushroom. The open reading frame of the cDNA consisted of 528 bp encoding 176 amino acids. In hemagglutination inhibition assay, α1-6 mannobiose was the strongest inhibitor and isomaltose, Glcα1-6Glc, was the second strongest one, among mono- and oligosaccharides tested. Frontal affinity chromatography indicated that HRL had the highest affinity for Manα1-6(Manα1-3)Manβ1-4GlcNAcβ1-4GlcNAc, and non-reducing terminal Manα1-6 was essential for the binding of HRL to carbohydrate chains. The sugar-binding specificity of HRL was also analyzed by using BIAcore. The result from the analysis exhibited positive correlations with that of the hemagglutination inhibition assay. All the results suggested that HRL recognized the α1-6 linkage of mannose and glucose, especially the Manα1-6 bond. HRL showed a mitogenic activity against spleen lymph cells of an F344 rat. Furthermore, an enzyme-linked immunosorbent assay showed strong binding of HRL to human immunodeficiency virus type-1 gp120.

Entomotoxic and nematotoxic lectins and protease inhibitors from fungal fruiting bodies

“…From fruiting bodies of the basidiomycetes Hygrophorus russula and Grifola frondosa, two mannose-specific lectins, termed H. russula lectin (HRL) and G. frondosa lectin (GFL), were isolated and characterized (Nagata et al 2005;Suzuki et al 2012). The amino acid sequence of these proteins is related to that of Jacalin from plants, and some plant members of this lectin family have recently been shown to protect the producing plants from herbivorous insects (Al Atalah et al 2014).…”

Isolation and Characterization of a Novel Mannose- and Fructose-Binding Lectin from the Edible Wild Mushroom Hygrophorus russula (Fr.) Quél.

“…HepG2 and MCF7 tumor cell lines (Wang et al, 2000;Zhang et al, 2009;Zhao et al, 2009) After we had commenced the present study on NHRL, a report (Suzuki et al, 2012). Both HRL and NHRL were adsorbed on cationic (S and SP) exchangers.…”

“…HRL and NHRL were similar in subunit molecular size and carbohydrate specificity. When the sequence of the first thirty N-terminal residues in NHRL is compared with that of the H. russula lectin reported in the literature (Suzuki et al, 2012), eleven different amino acid residues (shown in italics) are observed at corresponding positions in the sequences, indicating a 63.3% identity (Fig. 5).…”

“…been discovered (Bourne et al, 1999;Chu and Ng, 2006), only a very small number of mushroom lectins with mannose specificity have been demonstrated (Suzuki et al, 2012).…”

“…The mushrooms utilized by Suzuki et al (2012) and those employed in the present work might be from two different cultivars/strains. It has been shown that even lectins in fruiting bodies and mycelia of the same mushroom Tricholoma mongolicum displayed different characteristics .…”