Fig 7. Dose effect of CFH concentration on cofactor activity and comparison with THP cofactor activity.

(A) 8% SDS-PAGE silver-stained gel of DTT-reduced samples. All lanes had samples incubated at 37°C for 4 h and were loaded with 125 ng C3b and all lanes except Lane A contained 150 ng CFI. The chart below the lanes indicates the amount of CFH or THP present in the 10 μl samples, only half of which was loaded into the wells. Starred arrows indicate the degradation products of C3b. (B) Plot of CFH quantity versus intensity of band ratio obtained after Image J analysis of the intensity of the C3bα₆₂ fragment versus the C3b ß-chain in each lane (C → H). Dashed horizontal line indicates the band intensity ratio present in the 5 μg THP sample (Lane J).