Fig. 3
Hb-binding activity of plasma derived and recombinant Hp. a Human plasma derived Hp (left) or albumin (right) were immobilized on the SPR-Chip and tested for Hb-binding activity by surface plasmon resonance (SPR). The lines represent the association and dissociation signal curves of a range of Hb concentrations in the fluid-phase (0, 312.5, 625, 1250, 2500 and 5000 nM). b SPR analyses of rHp variants with (mut) and without cleavage-site mutations (left panels) with the corresponding size exclusion HPLC chromatographs (right panels). The blue lines represent the signals of the Hb + rHp mixtures, the red line shows the signal of Hb alone. All size exclusion HPLC traces are scaled identically to fit to the red Hb peak chromatogram. c Association (ka), dissociation (kd) and equilibrium (KD) constants for the SPR experiments