Red further for MS identification. Protein and peptide identifications obtained with the SEQUEST search algorithm with p,0.01 were considered statistically significant. To further validate SEQUEST identification, the location of protein spots (i.e., molecular weight [MW] and isoelectric point [pI]) on 2D-gels was manually checked based on MedChemExpress CI 1011 expected MW and pI values from BTZ-043 SwissProt database information.Results ProteomicsProteomics analysis using 2-DE and Sypro Ruby staining was performed on proteins isolated from brain mitochondria of WT and p53(2/2) mice to determine proteins differently expressed. Fig. 1 shows 2D-gel images related to these analyses, with expanded images of protein spots significantly different (p,0.05) between WT and p53(2/2). Twelve proteins were identified as differently expressed between WT and p53(2/2) mice, and interestingly all twelve of these proteins were significantly overexpressed in p53(2/2) samples. Surprisingly, we did not find any mitochondrial proteins down-regulated in p53(2/2) mice relative to WT. The protein spots of interest were excised from the gels, and following digestion with the trypsin peptide were subjected to MS/MS analyses. Proteins identified are listed in Table 1 with the number of peptide sequences, the score, the coverage, MW, pI, fold-change levels, and p-value. All protein identifications were consistent with comparison of protein positions on the gel with MW and pI from databases.Mass spectrometry (MS)Salts and contaminants were removed from tryptic peptide solutions using C18 ZipTips (Sigma-Aldrich, St. Louis, MO, USA), reconstituted to a volume of ,15 ml in a 50:50 water: acetonitrile solution containing 0.1 formic acid. Tryptic peptides were analyzed with an automated Nanomate electrospray ionization (ESI) [Advion Biosciences, Ithaca, NY, USA] Orbitrap XL MS (Thermo-Scientific, Waltham, MA, USA) platform. The Orbitrap MS was operated in a data-dependent mode whereby the eight most intense parent ions measured in the Fourier Transform (FT) at 60,000 resolution were selected for ion trap fragmentation with the following conditions: injection time 50 ms, 35 collision energy, MS/MS spectra were measured in the FT at 7500 resolution, and dynamic exclusion was set for 120 s. EachProteomics of p53-Regulated Pathways in BrainThe identified proteins were: guanine nucleotide-binding protein G (o) subunit alpha (212-fold qp53KO, *P,0.0019), ATP synthase subunit beta (125-fold qp53KO, *P,0.0035), heat shock cognate 71 (212-fold qp53KO, *P,0.002), aldehyde dehydrogenase family 5, subfamily A1 (131-fold qp53KO, *P,0.0009), glutamate dehydrogenase 1 (131-fold qp53KO, *P,0.0076), mitochondrial isoform of fumarate hydratase (325fold qp53KO, *P,0.0019), acetyl-CoA acetyltransferase (166fold qp53KO, *P,0.00079), isoform Mt-VDAC1 of voltagedependent anion-selective channel protein 1 (201-fold qp53KO, *P,0.0027), aspartate aminotransferase (210-fold qp53KO, *P,0.0037), Mn superoxide dismutase (133-fold qp53KO, *P,0.0026), cytochrome b-c1 complex Rieske subunit (252-fold qp53KO, *P,0.0030), and thioredoxin-dependent peroxide reductase (253-fold qp53KO, *P,0.0015).target to restore neuronal impairment. Since our investigation was performed on isolated brain mitochondria from p53(2/2) mice, our results conceivably could provide insights into progression of many mitochondrial-associated diseases. Hence, the identified proteins are involved in energy and mitochondrial alterations, signal transduction, ant.Red further for MS identification. Protein and peptide identifications obtained with the SEQUEST search algorithm with p,0.01 were considered statistically significant. To further validate SEQUEST identification, the location of protein spots (i.e., molecular weight [MW] and isoelectric point [pI]) on 2D-gels was manually checked based on expected MW and pI values from SwissProt database information.Results ProteomicsProteomics analysis using 2-DE and Sypro Ruby staining was performed on proteins isolated from brain mitochondria of WT and p53(2/2) mice to determine proteins differently expressed. Fig. 1 shows 2D-gel images related to these analyses, with expanded images of protein spots significantly different (p,0.05) between WT and p53(2/2). Twelve proteins were identified as differently expressed between WT and p53(2/2) mice, and interestingly all twelve of these proteins were significantly overexpressed in p53(2/2) samples. Surprisingly, we did not find any mitochondrial proteins down-regulated in p53(2/2) mice relative to WT. The protein spots of interest were excised from the gels, and following digestion with the trypsin peptide were subjected to MS/MS analyses. Proteins identified are listed in Table 1 with the number of peptide sequences, the score, the coverage, MW, pI, fold-change levels, and p-value. All protein identifications were consistent with comparison of protein positions on the gel with MW and pI from databases.Mass spectrometry (MS)Salts and contaminants were removed from tryptic peptide solutions using C18 ZipTips (Sigma-Aldrich, St. Louis, MO, USA), reconstituted to a volume of ,15 ml in a 50:50 water: acetonitrile solution containing 0.1 formic acid. Tryptic peptides were analyzed with an automated Nanomate electrospray ionization (ESI) [Advion Biosciences, Ithaca, NY, USA] Orbitrap XL MS (Thermo-Scientific, Waltham, MA, USA) platform. The Orbitrap MS was operated in a data-dependent mode whereby the eight most intense parent ions measured in the Fourier Transform (FT) at 60,000 resolution were selected for ion trap fragmentation with the following conditions: injection time 50 ms, 35 collision energy, MS/MS spectra were measured in the FT at 7500 resolution, and dynamic exclusion was set for 120 s. EachProteomics of p53-Regulated Pathways in BrainThe identified proteins were: guanine nucleotide-binding protein G (o) subunit alpha (212-fold qp53KO, *P,0.0019), ATP synthase subunit beta (125-fold qp53KO, *P,0.0035), heat shock cognate 71 (212-fold qp53KO, *P,0.002), aldehyde dehydrogenase family 5, subfamily A1 (131-fold qp53KO, *P,0.0009), glutamate dehydrogenase 1 (131-fold qp53KO, *P,0.0076), mitochondrial isoform of fumarate hydratase (325fold qp53KO, *P,0.0019), acetyl-CoA acetyltransferase (166fold qp53KO, *P,0.00079), isoform Mt-VDAC1 of voltagedependent anion-selective channel protein 1 (201-fold qp53KO, *P,0.0027), aspartate aminotransferase (210-fold qp53KO, *P,0.0037), Mn superoxide dismutase (133-fold qp53KO, *P,0.0026), cytochrome b-c1 complex Rieske subunit (252-fold qp53KO, *P,0.0030), and thioredoxin-dependent peroxide reductase (253-fold qp53KO, *P,0.0015).target to restore neuronal impairment. Since our investigation was performed on isolated brain mitochondria from p53(2/2) mice, our results conceivably could provide insights into progression of many mitochondrial-associated diseases. Hence, the identified proteins are involved in energy and mitochondrial alterations, signal transduction, ant.
