Skip to main content
. Author manuscript; available in PMC: 2009 Dec 1.
Published in final edited form as: J Am Soc Mass Spectrom. 2008 Aug 12;19(12):1875–1886. doi: 10.1016/j.jasms.2008.08.004

Figure 4. Disulfide bond linkage between C125 and C142 as determined by MS/MS spectrum of tryptic digests of the 51 kDa subunit of complex I.

Figure 4

Complex I was exposed to the conditions of superoxide production, and then alkylated by iodoacetamide as described in “Materials and Methods”. Crude NADH dehydrogenase (NDH) was prepared from complex I as described in the published procedure (16). The obtained crude NDH was subjected to SDS-PAGE under non-reducing conditions. The gel band of the 51 kDa polypeptide was subjected to in-gel digestion prior to LC/MS/MS as described in “Materials and Methods”. Chain A and Chain B represent peptides containing aa 112–128 and aa 138–147 respectively. A disulfide bond linking Chain A with Chain B is indicated in red. The sequence-specific ions are labeled as bnA (n=2–7) for Chain A, and ynB (n=3–5) for Chain B on the spectrum. M indicates Chain A plus Chain B.