Fig. 3.
SPR analysis of fBs purified from plasma. (a) Formation of C3bB complexes. Control fB (fBWT) and fB purified from H21 (fBK323E) formed similar levels of the proenzyme, whereas fB purified from H55P (fBF286L) formed C3bB complexes much more rapidly and to a much higher level. (b) Formation of C3bBb complexes. fBWT and fBK323E formed similar levels of complexes with C3b. fBF286L formed high and similar levels of complexes with C3b in the absence or presence of fD. Resp. Diff, response difference; RU, resonance units.