2D-DIGE global protein profiling of alcohol-dependent mouse brain

ABSTRACT: Data analysis. Spot detection and matching were performed with a comparative cross analysis of all the gels using DeCyder software v.6.5 (GE Healthcare). 178 spots were selected based on 1.15-fold for protein ratio cut-off, allowing for the appearance of the spots in 23 out of 28 gels (69 out of 84 total images). Data from 95 spots were submitted. 93 spots were identified with high confidence. Spot picking and Trypsin digestion. The spots of interest were picked up by Ettan Spot Picker (GE Healthcare) based on the in-gel analysis and spot picking design by DeCyder software. The gel spots were washed a few times then digested in-gel with modified porcine trypsin protease (Promega, Fitchburg, WI). The digested tryptic peptides were desalted using a Zip-tip C18 (Millipore, Billerica, MA). Peptides were eluted from the Zip-tip with 0.5 uL of matrix solution (alpha-cyano-4-hydroxycinnamic acid, 5 mg/mL in 50% acetonitrile, 0.1% trifluoroacetic acid, 25mM ammonium bicarbonate) and spotted on a MALDI plate. Mass Spectrometry. MALDI-TOF MS and TOF/TOF tandem MS/MS were performed on AB SCIEX TOF/TOF 5800 System (AB SCIEX). MALDI-TOF mass spectra were acquired in reflectron positive ion mode, averaging 4000 laser shots per spectrum. TOF/TOF tandem MS fragmentation spectra were acquired for each sample, averaging 4000 laser shots per fragmentation spectrum on each of the 7-10 most abundant ions present in each sample (excluding trypsin autolytic peptides and other known background ions). Database search. Both the resulting peptide mass and the associated fragmentation spectra were submitted to GPS Explorer workstation equipped with MASCOT search engine (Matrix Science, Boston, MA) to search the Swiss-Prot database. Searches were performed without constraining protein molecular weight or isoelectric point, with variable carbamidomethylation of cysteine and oxidation of methionine residues, and with one missed cleavage also allowed in the search parameters. Candidates with either protein score C.I.% or Ion C.I.% greater than 95 were considered significant. When multiple IDs were significant for a given spot, the selection was made by evaluating apparent molecular weight, isoelectric point, the location of the spot in the gel, and the presence of strips of multiple protein isoforms in the adjacent spots.

INSTRUMENT(S): instrument model

ORGANISM(S): Mus Musculus (mouse)

TISSUE(S): Brain

SUBMITTER: Giorgio Gorini  

LAB HEAD: Giorgio Gorini

PROVIDER: PXD000349 | Pride | 2014-07-28

REPOSITORIES: Pride