(clone # 4.3E8.D10, Golden, CO), monoclonal anti-β-actin antibody [clone # ACTN05 (C4)] from Abcam (Cambridge, MA), goat antibiotin serum for co-immunoprecipitation and horseradish peroxidase (HRP)-conjugated goat antibiotin antibody for Western blotting from Fitzgerald Industrial International Inc. (Concord, MA) and Cell Signaling Technology (Beverly, MA), respectively, and FITC-conjugated and -unconjugated donkey anti-mouse immunoglobulin

G (IgG) antibodies from Jackson ImmunoResearch Laboratories Inc. (Baltimore, MD). EZ-Link sulfo-NHS biotin for surface biotinylation, Compound Library order AminoLink plus immobilization kit for making affinity columns, and M-PER mammalian protein extraction reagent were purchased from Pierce (Rockford, IL), mammalian protease inhibitor cocktail and α-methyl click here mannose (methyl α-d mannopyranoside) from Sigma (St. Louis, MO), and protein A agarose fast flow bead from Upstate (Lake Placid, NY). Precision Plus Protein All Blue Standards from BioRad (Hercules, CA) was used for molecular weight standard. HBMEC were isolated and cultivated as described previously (Stins et al., 1997). The ability of E. coli strains to bind to HBMEC was examined

as described previously (Shin et al., 2005). To purify functionally active FimH, the copurification method with FimC, a periplasmic chaperon of type 1 pilus subunit proteins was used as described previously (Lee et al., 2005). FimC protein also was purified and used as a negative control. To prepare the affinity column, 1.5 mg FimCH or FimC proteins were covalently immobilized Depsipeptide price in a 1-mL bed-volume of AminoLink plus coupling beads in 0.1 M sodium citrate and 0.05 M sodium carbonate, pH 10. Surface biotinylation of HBMEC was performed on HBMEC monolayers grown on the plate as described in the manufacturer’s manual. HBMEC monolayers were washed with ice-cold phosphate-buffered saline and lysed with M-PER mammalian protein extraction reagent with mammalian protease inhibitor cocktail, and the insoluble debris was

removed by centrifugation (20 000 g at 4 °C). α-Methyl mannose (100 mM) was added to the lysate (10 mg), and the mixture was loaded onto the FimC (negative control)-immobilized column, which was equilibrated with M-PER reagent containing 100 mM α-methyl mannose (binding buffer). The FimC affinity column eliminates the nonspecific-interacting proteins with column beads and FimC protein as well as to minimize any effect of any mannose-binding proteins. The pass-through fractions were reloaded into the FimCH-immobilized column, and the column was washed with 10 bed-volume of the binding buffer. The FimH-binding proteins were eluted with 0.2 N glycine buffer, pH 2.5, and the elution fractions were neutralized with one-tenth volume of 1 M Tris, pH 9.5.