Conclusions 2-D PAGE studies might be extremely powerful for comparison of protein expression in different mycoplasma isolates, especially when considering that lipoproteins can be selectively

detected with this method, and that size and phase variations can be easily spotted through the application of powerful differential comparison approaches as the 2D DIGE. However, these need to be integrated with traditional Western immunoblotting and GeLC-MS/MS MM-102 for a deeper coverage and characterization of other mycoplasmal surface immunogens to be used as tools for vaccination, diagnosis, and therapy. This combined approach allowed the identification and characterization of 194 M. agalactiae proteins putatively localized on the membrane or associated to it, providing useful insights on its composition. In the future, alternative approaches such as blue native electrophoresis and chemical crosslinking of surface proteins will also enable to elucidate functional and structural aspects of membrane proteins that cannot be accounted for by the traditional gel-based proteomic approaches. Methods Bacterial strains and culture conditions At least three replicate cultures of Mycoplasma agalactiae PG2T and two Sardinian field isolates (named Bortigali and Nurri), were grown in PPLO medium supplemented MK-0457 mouse with 20% heat inactivated horse

serum and 500 μg/mL ampicillin, at 37°C with constant agitation. Mycoplasmas were collected by centrifugation (10 min at 10,000 × g at 4°C), and washed three times with PBS. At least three mycoplasma pellets were obtained from each bacterial culture replicate, and used for genetic and proteomic analyses. Total DNA was extracted from a set of pellets with DNeasy Blood & Tissue Kit (Qiagen), and subjected to FS1-FS2 PCR for species confirmation [51]. Total protein extracts and Triton X-114 fractionation

For total protein extracts, bacterial pellets were resuspended in 1% hot SDS, incubated for 3 minutes at 95°C, chilled, and diluted with lysis buffer (7 M urea, 2 M thiourea, 2.5% CHAPS, 2% ASB-14, 40 mM Tris-HCl pH 8.8, 1% IPG-buffer, protease inhibitors), and insoluble materials were discarded by centrifugation (10 min at 10,000 × g at 4°C) [52]. Hydrophilic and hydrophobic protein fractions were obtained Dolutegravir solubility dmso by Triton X-114 fractionation [29, 30] and ProteoPrep® Membrane Extraction Kit (Sigma-Aldrich). Proteins samples were quantified as described [52]. SDS-PAGE and 2-D PAGE SDS-PAGE was performed on 8% polyacrylamide gels on a Protean Tetra Cell (Bio-Rad) following the manufacturer instructions, and gels were stained with PageBlue™ Protein Staining Solution (Fermentas). Prior to 2-D PAGE, Triton X-114 fractions were BVD-523 clinical trial precipitated with methanol-chloroform [35] and resuspended in lysis buffer (8 M urea, 2 M thiourea, 2.5% CHAPS, 2% ASB-14, 40 mM Tris-HCl pH 8.8, 1% IPG-buffer, protease inhibitors).