The interaction between Factor H and C-reactive protein is important for innate immunity. C-reactive protein is a complement-related protein that recognizes damaged cells and bacterial pathogens and activates the classical complement pathway. The comparative ease of denaturation of C-reactive protein made experimental binding studies difficult. Some studies suggested that Factor H interacts with C-reactive protein, while others challenged this finding.A physiological interaction was determined using analytical ultracentrifugation, when the mixture of the two proteins inhibited Factor H oligomerization, indicating that C-reactive protein interacts with and blocks the Factor H dimerisation sites at SCR-6/8 and SCR-16/20. In the c(s) plots, the mixture of FH and CRP showed that new peaks A, B and C formed at different S values from those of peaks 1,2 and 3 in Factor H and peaks P and D for the pentamer and decamer of C-reactive protein.
Publications: Okemefuna, A.I., Nan, R., Miller, A. Gor, J. & Perkins, S.J. (2010) Complement Factor H binds at two independent sites to C-reactive protein in acute-phase concentrations. J. Biol. Chem 285, 1053-1065. JBC Paper of the Week.