Cobra venom factor
From Proteopedia
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Convertase formation is upregulated by CVF and is enhanced by the added stability of CVF when compared to native convertases. The absence of binding sites for factor H, factor I, complement receptor 1, decay-accelerating factor (DAF), and membrane co-factor protein in CVF may also contribute to its increased half-life. Factor H and CR1 binding sites in C3b depend on the presence of two glutamic acid residues E744 and E747 located in the MG6 domain. CVF, however, has aspartic acid and lysine residues in these corresponding locations: 728D and 731K. Similarly, segments of the TED domain are absent from CVF and contribute to the lack of binding ability by factor H. Additionally a binding site for properdin, a stabilizing protein, has been proposed at 1381-1414 of the beta chain. | Convertase formation is upregulated by CVF and is enhanced by the added stability of CVF when compared to native convertases. The absence of binding sites for factor H, factor I, complement receptor 1, decay-accelerating factor (DAF), and membrane co-factor protein in CVF may also contribute to its increased half-life. Factor H and CR1 binding sites in C3b depend on the presence of two glutamic acid residues E744 and E747 located in the MG6 domain. CVF, however, has aspartic acid and lysine residues in these corresponding locations: 728D and 731K. Similarly, segments of the TED domain are absent from CVF and contribute to the lack of binding ability by factor H. Additionally a binding site for properdin, a stabilizing protein, has been proposed at 1381-1414 of the beta chain. | ||
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== 3D Structures of Cobra venom factor == | == 3D Structures of Cobra venom factor == | ||
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Revision as of 16:47, 21 March 2013
Cobra Venom factor (CVF) is a stable functional co-factor of C3 and C5 convertases present in the venom of various rattle snake species. As part of the alternative pathway of immunological response to pathogens, C3 and C5 convertases are upregulated to induce the formation of membrane attack protein. CVF provides a functional and stable co-factor for convertase formation that can survive much longer than native co-factors and drastically increase the concentration of membrane attack protein which kills self cells and causes necrosis common to snake bites.
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3D Structures of Cobra venom factor
Updated on 21-March-2013
3pvm – CVF + hComplement C5
3frp – CVF α,β,γ chains
3hrz – CVF α,β,γ chains + hComplement C5 (mutant)
3hs0 – CVF α,β,γ chains + hComplement B (mutant)
3prx – CVF α,β,γ chains + hComplement C5 + superantigen-like protein 7
Proteopedia Page Contributors and Editors (what is this?)
Michal Harel, Gary A. Toumas, Alexander Berchansky, Joel L. Sussman
