After washing with probing buffer (25 mM Tris-HCl, pH 7

After washing with probing buffer (25 mM Tris-HCl, pH 7.5, 140 mM NaCl [TBS], 2.7 mM KCl, 1 mM CaCl2, 1 mM MnCl2, and 1% Triton X-100), the array was blocked with 60 l of rabbit normal IgG (50 g/ml) at 20C for 1 hour. different origins and four ES cell lines, but no binding was observed in either differentiated mouse feeder cells or somatic cells. The specific binding of rBC2LCN to podocalyxin prepared from a large set of iPS cells (138 types) and ES cells (15 types) was also confirmed using a high-throughput antibody-overlay lectin microarray. Alkaline digestion greatly reduced the binding of rBC2LCN to podocalyxin, indicating that the major glycan ligands of rBC2LCN are offered on (up to 80 mg/l) and can be purified to homogeneity in a one-step sugar-immobilized affinity chromatography approach [7]. rBC2LCN is usually highly specific to the defined glycan epitope Fuc1C2Gal1C3GlcNAc/GalNAc, which is usually contained in glycans such as H type 1 (sialidase (Roche, Indianapolis, IN, http://www.roche.com; catalog no. 10269611001, 1 l) 3-Hydroxyhippuric acid in PBST at 37C overnight and incubated with high-density lectin microarray at 20C overnight (supplemental online Fig. 3). After washing with probing buffer (25 mM Tris-HCl, pH 7.5, 140 mM NaCl [TBS], 2.7 mM KCl, 1 mM CaCl2, 1 mM MnCl2, and 1% Triton X-100), the array was blocked with 60 l of rabbit normal IgG (50 g/ml) at 20C for 1 hour. After washing again with probing buffer, the array was reacted with biotinylated goat anti-podocalyxin pAb (R&D; catalog no. AF1658) for 1 hour at 20C. After a further wash with probing buffer, bound anti-podocalyxin pAb was detected with 1 g/ml of Cy3-labeled streptavidin at 20C for 30 minutes. After washing with probing buffer, fluorescence images were acquired using an evanescent field-activated fluorescence scanner (GlycoStation Reader 1200; GP BioSciences, Sapporo, Japan, http://www.gpbio.jp/english/index.html). The fluorescence signal of each spot was quantified using Array Pro Analyzer ver.4.5 (Media Cybernetics, Bethesda, MD, http://www.mediacy.com), and the background value was subtracted. The lectin signals of triplicate spots were averaged and normalized to the mean value of 96 lectins immobilized around the array to adjust the data from each microarray to account for possible systematic variance [20, 25]. Gene Expression Analysis Total RNA was extracted from each cell sample using ISOGEN (Nippon Gene, Tokyo, Japan, http://www.nippongene.com). Global gene expression patterns were monitored using whole human genome microarray chips (G4112F; Agilent Technologies, Palo Alto, CA, http://www.agilent.com) with one-color (Cyanine 3) dye. 3-Hydroxyhippuric acid Hybridization was decided with a G2505C microarray scanner system (Agilent). The data were analyzed using GeneSpring GX12.0 software (Agilent). Each chip was normalized to the 75th percentile of measurement taken from the chip. Frontal Affinity Chromatography The theory and protocol of frontal affinity chromatography (FAC) have been explained previously [26, 27]. rBC2LCN was immobilized onto NHS-activated 3-Hydroxyhippuric acid Sepharose 4FF (GE Healthcare, Little Chalfont, U.K., http://www.gehealthcare.com), packed into a miniature column (inner diameter, 2 mm; length, 10 mm; bed volume, 31.4 l; Shimadzu, Kyoto, Japan, http://www.shimadzu.com), and connected to a high-performance liquid chromatograph (Shimadzu). Pyridylaminated (PA) glycans prepared from human iPS cells (201B7) were injected into the column. The elution profile was then detected by fluorescence (excitation, 285 nm; emission, 350 nm). The elution front of PA glycan relative to that of unfavorable control PA glycan (Man1C6(Man1C3)Man1C4GlcNAc1C4GlcNAc-PA), referred to as sialidase before application to the lectin microarray, because this treatment was found to enhance the conversation between podocalyxin and the immobilized rBC2LCN. This could be explained in part by reduced electric repulsion caused by the strong unfavorable charge of the greatly sialylated podocalyxin [30]. Using the advanced high-throughput technology, a series of cell samples including 138 types of human iPS cells prepared from six different origins with numerous passages (16C153 in supplemental online Table 1) and 15 types of human ES cells (154C168) were analyzed [20]. For reference (unfavorable control), mouse feeder cells (MEFs) (1) and differentiated somatic cells of the iPS origin (2C15) were also examined. Physique 4A shows the results of rBC2LCN binding for representative samples, that is, MEFs (1), fibroblasts (166), iPS cells (115), and ES Rabbit Polyclonal to B-Raf cells (154), whereas Physique 4B provides a bar graph representation of the total analysis. It was verified unambiguously that all of the iPS cells and ES cells examined bound to rBC2LCN, even though binding degrees were significantly varied. On the other hand, no detectable transmission was observed for rBC2LCN binding to feeder (1) or somatic cells (2C15) as expected, since podocalyxin was not immunoprecipitated from these cell samples (Fig. 3). These results confirm the fact that podocalyxin is usually a universal glycoprotein ligand of rBC2LCN in human undifferentiated pluripotent cells. Open in a separate window Physique 4. Podocalyxin is usually a.