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Factor H binds to the N-terminus of adiponectin and modulates complement activation
1Division of Medicine, Prince of Wales Hospital, Randwick, NSW 2031, Australia. P.Peake@unsw.edu.au
Biochemical and Biophysical Research Communications
|June 2, 2010
Summary
Adiponectin activates complement, but Factor H binding inhibits this potentially harmful response. This interaction protects against complement-mediated damage while preserving beneficial opsonization.
Area of Science:
- Immunology
- Biochemistry
Background:
- Adiponectin, an adipokine, activates the classical complement pathway.
- This activation can lead to pathophysiological consequences, including membrane attack complex formation.
Purpose of the Study:
- To investigate the interaction between adiponectin and the complement inhibitor Factor H.
- To determine if Factor H can modulate adiponectin-induced complement activation.
Main Methods:
- Assessed the binding of Factor H to adiponectin using purified proteins and human serum.
- Utilized heparin, a C3b homologue, and EDTA to study the interaction kinetics.
- Investigated binding across different adiponectin forms and a specific cleavage product.
Main Results:
- Adiponectin binds to Factor H in both purified and serum forms.
- The interaction is inhibited by heparin, a C3b homologue, and EDTA.
- Factor H binding effectively inhibits adiponectin-driven C3 and C5 convertases, reducing C5b-9 deposition.
Conclusions:
- Factor H acts as a crucial inhibitor of adiponectin-induced complement activation.
- This interaction mitigates potentially harmful complement effects while retaining beneficial opsonization functions.
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