Fig. 5.
Identification of succination sites in VDAC2. A, B, Mitochondrial-enriched fractions from Ndufs4 KO mouse brainstem were resolved by SDS-PAGE, gels were stained with Coomassie Brilliant Blue, bands at ∼30–35 kDa were excised, destained and digested with trypsin as described under “Experimental Procedures.” MS/MS spectra showing that Cys77 in the peptide YKWC2SCEYGLTFTEK of VDAC2 is endogenously succinated in vivo (A); the unmodified Cys77 in the peptide WCPEEYGLTFTEK was also identified after alkylation with 4-vinylpyridine (B). C, D, MS/MS spectra showing that Cys48 in the peptide SC2SCSGVEFSTSGSSNTDTGK of VDAC2 is endogenously succinated in vivo (C); the unmodified Cys48 in the peptide SCPESGVEFSTSGSSNTDTGK was also identified after alkylation with 4-vinylpyridine (D).