Figure 3: Percentages of peptidyl Cys reduction according to subcellular distribution. Peptides were assigned to either cytoplasmic, nuclear or mitochondrial compartments based upon IPA, Uniprot and literature searches. While the proportion of relatively oxidized Cys (about 20%) is similar among the compartments, a much greater percent of the mitochondrial Cys (19%) are highly reduced compared to the other compartments (about 6%). Note that the compartmental assignments represent only an approximation because some proteins have multiple distributions and others are more specifically associated with other subcellular structures. A. Cytoplasm. B. Nucleus. C. Mitochondria. See Online Supplement 1 for detailed data.