ADAMTS13 binds to SRCR1-5 and SRCR1-9 of CD163. Surface plasmon resonance analysis of the interaction between ADAMTS13 and CD163. (A) CD163 SRCR1-9 or (B) CD163 SRCR1-5 were immobilized on a CM5 chip. ADAMTS13 was then flowed over the chip in different concentrations. Graphs represent the binding curves using 100, 300, 500, 700, or 900 nM of ADAMTS13. Two independent experiments per concentration ADAMTS13 are displayed. Insets in panels A and B (upper right) show the concentration-dependent increase in maximal binding of ADAMTS13 to the CD163 SRCR1-9 and SRCR1-5 fragments. (C) EDHu-1 (100 nM) as a positive control was allowed to bind to immobilized SRCR1-9 and SRCR1-5 (EDHu-1 binds SRCR 3). Anti-ADAMTS13 antibody II-1 (500 nM) was used as a negative control.