Figure 2.

Factor H and factor-H-like protein 1 (FHL-1) bound to Aspergillus fumigatus enolase (AfEno1) maintain regulatory activity. (A) Factor H at indicated amounts was attached to immobilized AfEno1. After washing, C3b and factor I were added for 2 h and were separated by SDS-PAGE. C3b cleavage products were identified by western blotting with goat human C3 antiserum. Factor H bound to AfEno1 mediated C3b cleavage by factor I, and C3b cleavage products α′68 and α′43 kDa were identified dose dependently (lanes 3–5). When factor H was added to the negative control gelatin, no C3b cleavage products were observed (lane 2). (B) FHL-1 at increasing amounts was attached to AfEno1. Following washing, C3b and factor I were added for 2 h; the proteins were subjected to SDS-PAGE. After being transferred to a membrane, C3 cleavage products were visualized by western blotting. FHL-1 assisted in C3b cleavage by factor I, as revealed by the appearance of C3b cleavage products α′68, α′43, and α′41 (lanes 3–5). No C3b cleavage products were observed in the negative control gelatin (lane 2). Data shown in (A) and (B) are one representative result of three independent experiments.