Figure 6. Kinetics of NCD-4 modification of detergent-solubilized c-rings from F. nucleatum.

100 µM NCD-4 was added to a sample of purified F. nucleatum c₁₁ ring in MES buffer (pH 5.7) and 1.5% (w/v) n-octyl-β-D-glycoside. A continuous increase in fluorescence was measured upon reaction of NCD-4 with Glu65. Addition of 15 mM NaCl precluded further increase in the fluorescence. An extended control measurement, with no NaCl added, is shown in Figure S12.