Fig. 2: MFHR1I62 displays better C3b binding and cofactor activity than MFHR1V62.
From: A synthetic protein as efficient multitarget regulator against complement over-activation
a Binding to immobilized C5 was evaluated by ELISA with increasing concentrations of MFHR1I62 and MFHR1V62. Nonlinear regression using the sigmoidal equation and logarithmic transformed data showed no significant differences between both variants binding to C5 (P = 0.9328). Data represent mean values ± SD from 3 independent experiments. b Binding to immobilized C3b was evaluated by ELISA with increasing concentrations of MFHR1I62 and MFHR1V62. Nonlinear regression using the sigmoidal equation (dose–response curve, 4 parameters) showed significant differences between both variants binding to C3b (P = 0.0437). Data from one representative experiment are shown in Supplementary Fig. 7. c Cofactor activity of FI-mediated proteolytic cleavage of C3b α′-chain in the presence of MFHR1I62 or MFHR1V62 was visualized by SDS-PAGE and Coomassie staining. One representative experiment is shown. d Densitometric analysis of C3b cleavage. The amount of intact α′-chain was normalized for each sample with the β-chain and set to 100% intact C3b α′-chain at time zero. Two independent experiments were included in the analysis. e Double reciprocal plot of the percentage of intact C3b α′-chain. Linear regression analysis indicated significant differences between the MFHR1 variants (P = 0.0302).
