FIG. 2.

Analysis of in vitro protein-protein interactions by chemical cross-linking. VicH protein (100 μM) was incubated as described in Materials and Methods without any reagent (lane 2) or with EDC and NHS for 10, 30, and 60 min (lane 3 to 5, respectively) prior to quenching with β-mercaptoethanol and loading onto a 4 to 20% (wt/vol) gradient SDS-polyacrylamide gel. After electrophoresis for 1 h at 120 V, the gel was Coomassie blue stained. Lane 1, molecular weight markers (Bio-Rad).