Signature Sets', Minimal Fragment Sets for Identifying Protein Disulfide Structures with Cyanylation-Based Mass Mapping Methodology

Our cyanylation (CN)-based methodology for determining disulfide structure of cystinyl proteins overcomes the limitations of conventional proteolytic methods. However, the CN-based method has the potential drawback that occasionally some CN-induced cleavage fragments may not be detected. We show that CN-based methods can overcome the failure to detect fragments by demonstrating the existence of small ‘signature sets' of fragments. The link between signature sets and the robustness of CN-based methodology is validated by two case studies. Keywords: disulfide structure • cystinyl protein • signature sets • disulfide mass mapping