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== Function == | == Function == | ||
[https://www.uniprot.org/uniprot/CERU_HUMAN CERU_HUMAN] Ceruloplasmin is a blue, copper-binding (6-7 atoms per molecule) glycoprotein. It has ferroxidase activity oxidizing Fe(2+) to Fe(3+) without releasing radical oxygen species. It is involved in iron transport across the cell membrane. Provides Cu(2+) ions for the ascorbate-mediated deaminase degradation of the heparan sulfate chains of GPC1. May also play a role in fetal lung development or pulmonary antioxidant defense (By similarity). | [https://www.uniprot.org/uniprot/CERU_HUMAN CERU_HUMAN] Ceruloplasmin is a blue, copper-binding (6-7 atoms per molecule) glycoprotein. It has ferroxidase activity oxidizing Fe(2+) to Fe(3+) without releasing radical oxygen species. It is involved in iron transport across the cell membrane. Provides Cu(2+) ions for the ascorbate-mediated deaminase degradation of the heparan sulfate chains of GPC1. May also play a role in fetal lung development or pulmonary antioxidant defense (By similarity). | ||
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== Publication Abstract from PubMed == | |||
Copper-containing ferroxidase ceruloplasmin (Cp) forms binary and ternary complexes with cationic proteins lactoferrin (Lf) and myeloperoxidase (Mpo) during inflammation. We present an X-ray crystal structure of a 2Cp-Mpo complex at 4.7 A resolution. This structure allows one to identify major protein-protein interaction areas and provides an explanation for a competitive inhibition of Mpo by Cp and for the activation of p-phenylenediamine oxidation by Mpo. Small angle X-ray scattering was employed to construct low-resolution models of the Cp-Lf complex and, for the first time, of the ternary 2Cp-2Lf-Mpo complex in solution. The SAXS-based model of Cp-Lf supports the predicted 1:1 stoichiometry of the complex and demonstrates that both lobes of Lf contact domains 1 and 6 of Cp. The 2Cp-2Lf-Mpo SAXS model reveals the absence of interaction between Mpo and Lf in the ternary complex, so Cp can serve as a mediator of protein interactions in complex architecture. Mpo protects antioxidant properties of Cp by isolating its sensitive loop from proteases. The latter is important for incorporation of Fe(3+) into Lf, which activates ferroxidase activity of Cp and precludes oxidation of Cp substrates. Our models provide the structural basis for possible regulatory role of these complexes in preventing iron-induced oxidative damage. | |||
Ceruloplasmin: macromolecular assemblies with iron-containing acute phase proteins.,Samygina VR, Sokolov AV, Bourenkov G, Petoukhov MV, Pulina MO, Zakharova ET, Vasilyev VB, Bartunik H, Svergun DI PLoS One. 2013 Jul 3;8(7):e67145. doi: 10.1371/journal.pone.0067145. Print 2013. PMID:23843990<ref>PMID:23843990</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
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==See Also== | ==See Also== | ||
*[[Ceruloplasmin|Ceruloplasmin]] | *[[Ceruloplasmin|Ceruloplasmin]] | ||
== References == | |||
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</StructureSection> | </StructureSection> | ||