[HTML][HTML] Functional properties of complement factor H-related proteins FHR-3 and FHR-4: binding to the C3d region of C3b and differential regulation by heparin
J Hellwage, TS Jokiranta, V Koistinen, O Vaarala… - FEBS letters, 1999 - Elsevier
The human factor H-related proteins FHR-3 and FHR-4 are members of a family of proteins
related to the complement factor H. Here, we report that the two proteins bind to the C3d
region of complement C3b. The apparent KA values for the interactions of FHR-3 and FHR-4
with C3b are 7.5× 106 M− 1 and 2.9× 106 M− 1, respectively. Binding studies performed with
C3b-coated pneumococci confirmed the results obtained with the biosensor system. A C-
terminal construct of factor H showed similar binding characteristics. The interaction of FHR …
related to the complement factor H. Here, we report that the two proteins bind to the C3d
region of complement C3b. The apparent KA values for the interactions of FHR-3 and FHR-4
with C3b are 7.5× 106 M− 1 and 2.9× 106 M− 1, respectively. Binding studies performed with
C3b-coated pneumococci confirmed the results obtained with the biosensor system. A C-
terminal construct of factor H showed similar binding characteristics. The interaction of FHR …
The human factor H-related proteins FHR-3 and FHR-4 are members of a family of proteins related to the complement factor H. Here, we report that the two proteins bind to the C3d region of complement C3b. The apparent KA values for the interactions of FHR-3 and FHR-4 with C3b are 7.5×106 M−1 and 2.9×106 M−1, respectively. Binding studies performed with C3b-coated pneumococci confirmed the results obtained with the biosensor system. A C-terminal construct of factor H showed similar binding characteristics. The interaction of FHR-3, but not of FHR-4, with opsonised pneumococci was inhibited by heparin.
Elsevier