期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2004
卷号：101
期号：24
页码：8924-8929
DOI：10.1073/pnas.0400744101
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Vaccinia virus complement control protein (VCP), a homolog of the regulators of the complement activation family of proteins, inhibits complement activation through mechanisms similar to human fluid-phase complement regulators factor H and C4b-binding protein. VCP has a heparin-binding activity that assists vaccinia in host interactions. Interaction with cell-surface polyanions like heparin is centrally important in the functioning of fluid-phase complement regulators and is the basis of host-target discrimination by the alternative pathway. We report the structure of VCP in complex with a heparin decasaccharide, which reveals changes in VCP that might be pertinent to complement regulation. Properties that VCP shares with fluid-phase complement regulators suggest that such conformational changes may be of relevance in the functioning of other complement regulators. Additionally, comparison of VCP-heparin interactions with potentially similar interactions in factor H might enable understanding of the structural basis of familial hemolytic uremic syndrome, attributed to mutational disruption of heparin and C3b binding by factor H.
