3ZUI image
Entry Detail
PDB ID:
3ZUI
Keywords:
Title:
OMCI in complex with palmitoleic acid
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2011-07-19
Release Date:
2012-08-01
Method Details:
Experimental Method:
Resolution:
1.71 Å
R-Value Free:
0.22
R-Value Work:
0.19
R-Value Observed:
0.19
Space Group:
P 21 21 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:COMPLEMENT INHIBITOR
Chain IDs:A
Chain Length:150
Number of Molecules:1
Biological Source:ORNITHODOROS MOUBATA
Ligand Molecules
Primary Citation
Bifunctional Lipocalin Ameliorates Murine Immune Complex-Induced Acute Lung Injury.
J.Biol.Chem. 288 18789 ? (2013)
PMID: 23625922 DOI: 10.1074/JBC.M112.420331

Abstact

Molecules that simultaneously inhibit independent or co-dependent proinflammatory pathways may have advantages over conventional monotherapeutics. OmCI is a bifunctional protein derived from blood-feeding ticks that specifically prevents complement (C)-mediated C5 activation and also sequesters leukotriene B4 (LTB4) within an internal binding pocket. Here, we examined the effect of LTB4 binding on OmCI structure and function and investigated the relative importance of C-mediated C5 activation and LTB4 in a mouse model of immune complex-induced acute lung injury (IC-ALI). We describe two crystal structures of bacterially expressed OmCI: one binding a C16 fatty acid and the other binding LTB4 (C20). We show that the C5 and LTB4 binding activities of the molecule are independent of each other and that OmCI is a potent inhibitor of experimental IC-ALI, equally dependent on both C5 inhibition and LTB4 binding for full activity. The data highlight the importance of LTB4 in IC-ALI and activation of C5 by the complement pathway C5 convertase rather than by non-C proteases. The findings suggest that dual inhibition of C5 and LTB4 may be useful for treatment of human immune complex-dependent diseases.

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Primary Citation of related structures