Staphylococcal enterotoxin-like X (SElX) is a unique superantigen with functional features of two major families of staphylococcal virulence factors
Fig 2
Analysis of host binding by affinity precipitation.
(A) SDS-PAGE (12.5%) run under reducing and denaturing conditions of proteins from the various indicated human and mouse sources isolated by affinity with SElX2, SElX2-T130A, SSL6, SSL6-R181A, SSL11, or SSL11-T168A coupled to sepharose. Sepharose alone (control) was used as a control for non-specific binding. * indicates SELX/SSL that has dissociated from the sepharose. Marker is BenchMark Protein Ladder (Life Technologies). (B) The 40 top scoring leukocyte proteins identified by SElX-sepharose affinity binding are shown by descending rank in the bar graph and listed in order in the accompanying table. The ranking is based on the Unused Score (taken from S1 Table) given to each uniquely identified protein as calculated by the mass spectrometry analysis software ProteinPilot 5.0 (AB Sciex Pte. Ltd). The Unused Score indicates how much of the Total Score is unique to the particular protein hit. The Total Score is the sum of the Contrib values (contrib = the highest scoring peptide match for a peptide sequence) and determines the overall confidence for the protein identification. A and B are the Unused Scores of additional proteins identified in both the SElX-T130A/R141A and sepharose control samples with their corresponding Unused Scores from the SElX sample.