bovis BCG Moreau provides valuable information regarding specific proteins, many of which have been implicated in protective immune responses, and helps defining candidates for future vaccination strategies. Methods Bacterial strains and growth conditions Mycobacterium bovis BCG Pasteur 1173P2 was obtained from the Pasteur Institute

(Paris, France) culture collection, and stocks were maintained at -80°C. Mycobacterium bovis BCG Moreau was provided by Fundação Ataulpho de Paiva (FAP). Both strains were cultured as surface pellicles, for 2 weeks at 37°C, in 100 ml of Sauton vaccine production medium, provided by FAP. Sample BAY 73-4506 mouse preparation Culture filtrate proteins (CFPs) were obtained after separation of culture supernatants from the bacterial pellicles and subsequent centrifugation at 2,500 × g for 10 min at 4°C. The resulting supernatant was filtered through a 0.22 μm low protein binding membrane (Millipore Express; Millipore, Bedford, MA, USA) in order to remove any remaining bacteria. CFPs (on average 5.5 mg total protein) were precipitated with 17% (v/v) TCA and washed with cold acetone. Finally, proteins were dissolved in 1.5 ml of IEF buffer (8 M urea, 2% CHAPS, 4 mM tributylphosphine [TBP], 0.4% ampholytes pH 3-10) for 1 h at room temperature. Lumacaftor price Protein concentration

was determined using the RC-DC Kit (Bio-Rad). Proteins were stored at -80°C until analysis. Two dimensional gel electrophoresis (2DE) IPG strips and all 2DE reagents were purchased from Bio-Rad (Hercules, CA, USA). Isoelectric focusing was performed at 20°C on 17 cm

IPG strips, using 500 μg of CFPs diluted in a final volume of 300 μl in rehydration buffer (8 M urea, 2% CHAPS, 4 mM TBP, 0.4% ampholytes pH 3-10). Samples were applied to IPG strips (pH intervals of 3-6, 4-7 and 5-8) by in-gel rehydration and incubated for 1 h at room temperature. Isoelectric focusing was performed on a Protean® IEF cell (Bio-Rad) with maximum current of 50 μA/strip. Focusing parameters used for IPG strips in the pH range 4-7 and 5-8 were: active rehydration (50 V) for 11 h; step 1- linear gradient from 1 to 250 V over 20 min; step 2 – linear gradient from 250 to 10,000 V over 2 h; step 3- constant 10,000 V until 80,000 Vh was achieved. For IPG strips in Calpain the pH range 3-6, step 3 was constant 10,000 V until 60,000 Vh was achieved. After isoelectric focusing, proteins were reduced in 130 mM DTT and alkylated in 270 mM iodoacetamide, both in equilibration buffer (6 M urea, 2% SDS, 375 mM Tris-HCl pH 8.8, 20% glycerol). Second dimension separation was done in 17 cm, 12% or 15% SDS-PAGE gels, 1.0 mm thick, using a vertical system (Bio-Rad) in standard Laemli buffer [84] at 40 mA/gel, 10°C, until the tracking dye left the gel. Protein visualization and image analysis Gels were stained with colloidal Coomassie Brilliant Blue G-250 essentially as described [85], and documented using a GS-800™ auto-calibrating imaging densitometer (Bio-Rad).