Fig. 6.

Representative iTRAQ spectra and Western blot analysis. Isolated mitochondrial subpopulations from WT and db/db hearts were labeled with iTRAQ reagents [114 (db/db SSM), 115 (db/db IFM), 116 (WT SSM), and 117 (WT IFM)] and combined for analysis with mass spectrometry. A: representative spectra of the simultaneous quantitation of cytochrome c oxidase subunit VIIa1 peptide in WT and db/db mitochondrial subpopulations. B: spectra for the reporter groups of the iTRAQ reagents (114, 115, 116, and 117) from cytochrome c oxidase subunit VIIa1 peptide mass spectrometry (MS)/MS spectra. These spectra were used along with other peptides to simultaneously quantify cytochrome c oxidase subunit VIIa1 in WT and db/db mitochondrial subpopulations. C and D: representative Western blots (top) and densitometric analyses (bottom) of cytochrome c oxidase subunit VIIa1 in SSM (C) and IFM (D) from WT and db/db hearts. Values are means ± SE; n = 5 for each group. *P < 0.05 for WT vs. db/db.