7wki
From Proteopedia
(Difference between revisions)
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| - | '''Unreleased structure''' | ||
| - | + | ==Structure of the ultra-affinity complex between CFH and a nanobody== | |
| + | <StructureSection load='7wki' size='340' side='right'caption='[[7wki]], [[Resolution|resolution]] 2.60Å' scene=''> | ||
| + | == Structural highlights == | ||
| + | <table><tr><td colspan='2'>[[7wki]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [https://en.wikipedia.org/wiki/Vicugna_pacos Vicugna pacos]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7WKI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7WKI FirstGlance]. <br> | ||
| + | </td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=7wki FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7wki OCA], [https://pdbe.org/7wki PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7wki RCSB], [https://www.ebi.ac.uk/pdbsum/7wki PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7wki ProSAT]</span></td></tr> | ||
| + | </table> | ||
| + | == Disease == | ||
| + | [https://www.uniprot.org/uniprot/CFAH_HUMAN CFAH_HUMAN] Genetic variations in CFH are associated with basal laminar drusen (BLD) [MIM:[https://omim.org/entry/126700 126700]; also known as drusen of Bruch membrane or cuticular drusen or grouped early adult-onset drusen. Drusen are extracellular deposits that accumulate below the retinal pigment epithelium on Bruch membrane. Basal laminar drusen refers to an early adult-onset drusen phenotype that shows a pattern of uniform small, slightly raised yellow subretinal nodules randomly scattered in the macula. In later stages, these drusen often become more numerous, with clustered groups of drusen scattered throughout the retina. In time these small basal laminar drusen may expand and ultimately lead to a serous pigment epithelial detachment of the macula that may result in vision loss. Defects in CFH are the cause of complement factor H deficiency (CFHD) [MIM:[https://omim.org/entry/609814 609814]. A disorder that can manifest as several different phenotypes, including asymptomatic, recurrent bacterial infections, and renal failure. Laboratory features usually include decreased serum levels of factor H, complement component C3, and a decrease in other terminal complement components, indicating activation of the alternative complement pathway. It is associated with a number of renal diseases with variable clinical presentation and progression, including membranoproliferative glomerulonephritis and atypical hemolytic uremic syndrome.<ref>PMID:9312129</ref> <ref>PMID:10803850</ref> <ref>PMID:11170895</ref> <ref>PMID:11170896</ref> <ref>PMID:11158219</ref> <ref>PMID:12020532</ref> <ref>PMID:14978182</ref> <ref>PMID:16612335</ref> Defects in CFH are a cause of susceptibility to hemolytic uremic syndrome atypical type 1 (AHUS1) [MIM:[https://omim.org/entry/235400 235400]. An atypical form of hemolytic uremic syndrome. It is a complex genetic disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, renal failure and absence of episodes of enterocolitis and diarrhea. In contrast to typical hemolytic uremic syndrome, atypical forms have a poorer prognosis, with higher death rates and frequent progression to end-stage renal disease. Note=Susceptibility to the development of atypical hemolytic uremic syndrome can be conferred by mutations in various components of or regulatory factors in the complement cascade system. Other genes may play a role in modifying the phenotype.<ref>PMID:14978182</ref> <ref>PMID:9551389</ref> <ref>PMID:10577907</ref> <ref>PMID:10762557</ref> <ref>PMID:11851332</ref> <ref>PMID:14583443</ref> <ref>PMID:12960213</ref> <ref>PMID:20513133</ref> Genetic variation in CFH is associated with age-related macular degeneration type 4 (ARMD4) [MIM:[https://omim.org/entry/610698 610698]. ARMD is a multifactorial eye disease and the most common cause of irreversible vision loss in the developed world. In most patients, the disease is manifest as ophthalmoscopically visible yellowish accumulations of protein and lipid (known as drusen) that lie beneath the retinal pigment epithelium and within an elastin-containing structure known as Bruch membrane.<ref>PMID:22019782</ref> | ||
| + | == Function == | ||
| + | [https://www.uniprot.org/uniprot/CFAH_HUMAN CFAH_HUMAN] Factor H functions as a cofactor in the inactivation of C3b by factor I and also increases the rate of dissociation of the C3bBb complex (C3 convertase) and the (C3b)NBB complex (C5 convertase) in the alternative complement pathway. | ||
| + | <div style="background-color:#fffaf0;"> | ||
| + | == Publication Abstract from PubMed == | ||
| + | Atypical hemolytic uremic syndrome (aHUS) is a disease associated with dysregulation of the immune complement system, especially of the alternative pathway (AP). Complement factor H (CFH), consisting of 20 domains called complement control protein (CCP1-20), downregulates the AP as a cofactor for mediating C3 inactivation by complement factor I. However, anomalies related to CFH are known to cause excessive complement activation and cytotoxicity. In aHUS, mutations and the presence of anti-CFH autoantibodies (AAbs) have been reported as plausible causes of CFH dysfunction, and it is known that CFH-related aHUS carries a high probability of end-stage renal disease. Elucidating the detailed functions of CFH at the molecular level will help to understand aHUS pathogenesis. Herein, we used biophysical data to reveal that a heavy-chain antibody fragment, termed VHH4, recognized CFH with high affinity. Hemolytic assays also indicated that VHH4 disrupted the protective function of CFH on sheep erythrocytes. Furthermore, X-ray crystallography revealed that VHH4 recognized the Leu1181-Leu1189(CCP20) loop, a known anti-CFH AAbs epitope. We next analyzed the dynamics of the C-terminal region of CFH and showed that the epitopes recognized by anti-CFH AAbs and VHH4 were the most flexible regions in CCP18-20. Finally, we conducted mutation analyses to elucidate the mechanism of VHH4 recognition of CFH and revealed that VHH4 inserts the Trp1183(CCP20) residue of CFH into the pocket formed by the complementary determining region 3 loop. These results suggested that anti-CFH AAbs may adopt a similar molecular mechanism to recognize the flexible loop of Leu1181-Leu1189(CCP20), leading to aHUS pathogenesis. | ||
| - | + | Antibody recognition of complement factor H reveals a flexible loop involved in atypical hemolytic uremic syndrome pathogenesis.,Yokoo T, Tanabe A, Yoshida Y, Caaveiro JMM, Nakakido M, Ikeda Y, Fujimura Y, Matsumoto M, Entzminger K, Maruyama T, Okumura CJ, Nangaku M, Tsumoto K J Biol Chem. 2022 Jun;298(6):101962. doi: 10.1016/j.jbc.2022.101962. Epub 2022 , Apr 20. PMID:35452676<ref>PMID:35452676</ref> | |
| - | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
| - | [[Category: | + | </div> |
| + | <div class="pdbe-citations 7wki" style="background-color:#fffaf0;"></div> | ||
| + | == References == | ||
| + | <references/> | ||
| + | __TOC__ | ||
| + | </StructureSection> | ||
| + | [[Category: Homo sapiens]] | ||
| + | [[Category: Large Structures]] | ||
| + | [[Category: Vicugna pacos]] | ||
| + | [[Category: Caaveiro JMM]] | ||
| + | [[Category: Tsumoto K]] | ||
| + | [[Category: Yokoo T]] | ||
Revision as of 10:08, 24 November 2022
Structure of the ultra-affinity complex between CFH and a nanobody
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