Figure 4.

Both D90G and R53C have defects in CA. (A) D90G has a significant defect in co-factor activity (CA) (P < 0.01 at all time points, two-tailed t-test). (B) R53C has lower CA in the fluid phase assay (P > 0.05 at all time points, two-tailed t-test). (C) R53C also has a significant defect in CA in a hemolysis based assay. For (A) and (B), quantitation of the α′ produced over time relative to the amount of α′ present originally. These are the average of four independent experiments; error bars represent one standard deviation. Quantification was done by densitometrically scanning the α′ bands and normalizing to the amount of C3b in that lane (β chain).