Table 2.

Specificity and affinity^a of the N- and C-terminal regions of Factor H for different C3 fragments.

C3 fragment	Kd (μM)b
	Factor H domains 1–6	Factor H domain 19-20
C3	0.4 ± 0.05	NDBc
C3b	0.08 ± 0.04	1.7 ± 0.1
iC3b	5.0 ± 2.2	2.8 ± 0.3
C3c	NDBc	NDBc
C3d	NDBc	1.9 ± 0.1

^aBinding data was generated as in Figure 3 and K_d values were determined as in Figure 4 for the recombinantly generated Factor H fragments indicated.

^bStandard errors from non-linear regression analysis are reported.

^cNDB indicates “No Detectable Binding” was observed.