The interaction between factor H and Von Willebrand factor.

Autor: Shuju Feng, Xiaowen Liang, Miguel A Cruz, Hangoc Vu, Zhou Zhou, Naresh Pemmaraju, Jing-Fei Dong, Michael H Kroll, Vahid Afshar-Kharghan
Jazyk: angličtina
Rok vydání: 2013
Předmět:
Zdroj: PLoS ONE, Vol 8, Iss 8, p e73715 (2013)
Druh dokumentu: article
ISSN: 1932-6203
DOI: 10.1371/journal.pone.0073715
Popis: Complement factor H (fH) is a plasma protein that regulates activation of the alternative pathway, and mutations in fH are associated with a rare form of thrombotic microangiopathy (TMA), known as atypical hemolytic uremic syndrome (aHUS). A more common TMA is thrombotic thrombocytopenic purpura, which is caused by the lack of normal ADAMTS-13-mediated cleavage of von Willebrand factor (VWF). We investigated whether fH interacts with VWF and affects cleavage of VWF. We found that factor H binds to VWF in plasma, to plasma-purified VWF, and to recombinant A1 and A2 domains of VWF as detected by co-immunoprecipitation (co-IP) and surface plasmon resonance assays. Factor H enhanced ADAMTS-13-mediated cleavage of recombinant VWF-A2 as determined by quantifying the cleavage products using Western-blotting, enhanced cleavage of a commercially available fragment of VWF-A2 (FRETS-VWF73) as determined by fluorometric assay, and enhanced cleavage of ultralarge (UL) VWF under flow conditions as determined by cleavage of VWF-platelet strings attached to histamine stimulated endothelial cells. Using recombinant full-length and truncated fH molecules, we found that the presence of the C-terminal half of fH molecule is important for binding to VWF-A2 and for enhancing cleavage of the A2 domain by ADAMTS-13. We conclude that factor H binds to VWF and may modulate cleavage of VWF by ADAMTS-13.
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