Figures & data
Figure 1. Sequential digestion of C3, generating C3b, iC3b, C3c, C3dg, and C3d. Activation of C3 leads to disruption of the thiol ester (TE circular), which then establishes covalent bonds (TE linear). The interchain disulfide bonds are indicated (S S).
Figure 2. Epitope expression of human C3 bound to adsorbed human IgG. Human serum was added in 3-fold serial dilution from 100% and incubated at 37°C for 60 min (panel A) or 120 min (panel B). Bound C3 was detected using pAbs anti-C3d (filled triangles) and anti-C3c (open triangles), and mAbs 7D323.1 (squares), 7D18.1 (circles), 7D264.6 (open diamonds), and 7D84.1 (filled diamonds).
Figure 3. Binding of CR1 (panel A), anti-C3 mAb 7D18.1 (panel B), CR2 (panel C), and anti-C3 mAb 7D323.1 (panel D) to human C3 bound to adsorbed human IgG. Human serum (in 3-fold serial dilution from 100%) was added and incubated at 37°C for 2.5 min (dashed lines) or 60 min (solid lines).
Figure 4. Binding of CR1 (panel A) and anti-C3 mAb 7D18.1 (panel B) and of CR2 (panel C) and anti-C3 mAb 7D323.1 (panel D) to human C3 fragments bound to adsorbed human IgG. The coated surfaces were incubated first with human serum in 3-fold serial dilution from 100% at 37°C for 60 min. After washing, heat-inactivated human serum was then added, together with buffer (solid lines) or soluble CR1 to enable digestion of deposited iC3b to C3dg (dashed lines).
Figure 5. Electrophoretic pattern of polypeptide chains from the various C3 fragments. The molecular weights (Mw) of the standards are indicated.
Figure 6. Western blot analysis of C3 fragments eluted from an IgG-coated surface exposed to undiluted human serum for 0, 5, 10, 20, or 60 min, detected using: pAb anti-C3d (panel A), mAb anti-C3 7D264.6 (panel B), and pAb anti-C3c (panel C). Reference preparations of C3, C3b, and iC3b were also analyzed, and the molecular weights (Mw) of the standards are indicated.
