Supplementary Figure 9: Specific proteases outperformed nonspecific proteases in disulfide-bond analysis of complex protein samples.

(a) Number of disulfide bonds identified from an E. coli periplasmic fraction using different proteases. Number of unique identifications is shown in parentheses. (b) The search space and time cost for each protease digestion tested. Similar amounts of HCD spectra were collected from different protease digestions, and they were all searched against the same E. coli database using the same hardware setup (computer cluster, 6 units of Dual Xeon 5405, 2.0 GHz, 4G RAM, 8 core/unit) and the same pLink-SS parameters except for the protease specificity setting.