Binding assay Various GSLs were adsorbed on 96-well plates (Falcon Microtest III flexible assay plates, Oxnard, CA). Solutions (25 μl/well, 100 ng/first well) in ethanol of different GSLs were serially diluted, dried at 37°C and wells blocked with 1% bovine serum albumin (BSA) in 0.01 M phosphate-buffered saline (PBS), pH 7.2 (200 μl) for 2 h, and sequentially incubated with mAb MEST-3 (100 μl) overnight at 4°C, rabbit anti-mouse IgG (50 μl) for 2 h, and with 50 μl of 125I-labeled protein A in PBS with 1% of BSA (about 105 cpm/well) for 1 h. The amount of mAb MEST-3 bound to Pb-2

was determined by measuring the radioactivity in each well in a gamma counter [13]. Release of glycosylinositols by ammonolysis Ammonolysis of GIPCs was performed as described by Barr and Lester [8] and Levery et Doxorubicin supplier Selleck Galunisertib al. [11]. Briefly, 100 μg of GIPCs Pb-2 and Ss-Y2 were heated in a Teflon-lined screw-capped test tube with 10 N NH3.H20 (~ 1 mL) for 18 h at 150°C. The solution was cooled and evaporated under N2 stream at 37°C; this process was repeated after addition of a few drops of 2-propanol. The residue was sonicated in 1 mL of water and the lipophilic components were removed by passage of this solution through a small C18-silica solid-phase extraction cartridge, washing twice with 1 ml of water. The combined aqueous fraction containing free glycosylinositol was lyophilized and used for inhibition of antibody binding

to GIPCs Pb-2. Inhibition of antibody binding by different methyl glycosides, disaccharides and glycosylinositols Initially, 75 μl of a 200 mM solution of several methyl-α- and β-D-glycosides (glucopyranoside, galactopyranoside and mannopyranoside), disaccharides (Manα1→2Man, Manα1→3Man and

Manα1→6Man), purchased from Sigma (MO, USA), and the glycosylinositols (Manα1→3Manα1→2Ins and Manα1→3Manα1→6Ins, described above), were serially diluted with PBS in a 96-well plate. Each glycoside solution was incubated with 75 μl of MEST-3 at room temperature [35]. After 2 h, aliquots of 100 μl were taken and incubated overnight at 4°C in 96-well plates pre-coated with the GIPC Pb-2 (100 ng/well) over essentially as described under Binding assay. Periodate oxidation Ninety-six-well plates were coated with different concentrations (100 ng to 5 pg) of GIPC Pb-2 and treated with 5 and 20 mM of sodium m-periodate in PBS (0.1 M, pH 7.0) at room temperature for 30 min [13]. The plates were washed with PBS, reduced with NaBH4 (50 mM in PBS) during 30 min, blocked with 5% of BSA in PBS for 1 h, and incubated overnight with mAb MEST-3, and processed as described in Binding Assay. High performance thin layer chromatography (HPTLC) immunostaining GIPCs purified from different fungi were separated by HPTLC, and the immunostaining of the plates was performed by the procedure of Magnani et al. [38], modified by Zuolo et al. [39] and Takahashi et al. [40].