Figure 5.
Decay-accelerating and cofactor activities of I62-CFH and V62-CFH on ES. A, activated ES were preloaded with C3bBb. The C3bBb-decorated cells were exposed to a CFH concentration series, followed by a hemolysis-based estimate of remaining C3bBb. This allowed derivation of IC50 values for DAA on a hostlike cell surface. B, C3b-preloaded activated ES surfaces were treated with CFI and a range of CFH concentrations, providing an estimate of the CA of CFH on a hostlike cell surface. C, the DAA assay used in A was repeated, but using I62-CFH mixed (1:2) with PspCN. The curve for I62-CFH alone is included for comparison. D, the CA assay used in B was repeated, but using I62-CFH mixed (1:2) with PspCN. The curve for I62-CFH alone is included for comparison. The mean and S.D. (error bars) of triplicate measurements are plotted, and sigmoidal curves were fitted using SigmaPlot. Each graph is representative of two experiments, except for A and D, which show data from single experiments.