Table 3.

Affinity^a of Factor H polyanion binding sites^b for heparin.

Factor H domains	Kd (μM)c
CCP 1-20	0.49 ± 0.08
CCP 6-8	1.2 ± 0.08
CCP 11-13	17 ± 3.3
CCP 18-20	4.9 ± 0.7

^aBinding regions were identified as described in Figure 7 and K_d values were determined as described in Supplementary Figure 2 for full-length Factor H and the trimeric recombinant proteins.

^bThree domain recombinant proteins were expressed in yeast and purified as described in Experimental Procedures.

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