1ar2

From Proteopedia

(Difference between revisions)

Current revision

DISULFIDE-FREE IMMUNOGLOBULIN FRAGMENT

Structural highlights

1ar2 is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 2.8Å
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

KVD33_HUMAN V region of the variable domain of immunoglobulin light chains that participates in the antigen recognition (PubMed:24600447). Immunoglobulins, also known as antibodies, are membrane-bound or secreted glycoproteins produced by B lymphocytes. In the recognition phase of humoral immunity, the membrane-bound immunoglobulins serve as receptors which, upon binding of a specific antigen, trigger the clonal expansion and differentiation of B lymphocytes into immunoglobulins-secreting plasma cells. Secreted immunoglobulins mediate the effector phase of humoral immunity, which results in the elimination of bound antigens (PubMed:20176268, PubMed:22158414). The antigen binding site is formed by the variable domain of one heavy chain, together with that of its associated light chain. Thus, each immunoglobulin has two antigen binding sites with remarkable affinity for a particular antigen. The variable domains are assembled by a process called V-(D)-J rearrangement and can then be subjected to somatic hypermutations which, after exposure to antigen and selection, allow affinity maturation for a particular antigen (PubMed:20176268, PubMed:17576170).^[1] ^[2] ^[3] ^[4]

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

BACKGROUND: Immunoglobulin domains owe a crucial fraction of their conformational stability to an invariant central disulfide bridge, the closure of which requires oxidation. Under the reducing conditions prevailing in cell cytoplasm, accumulation of soluble immunoglobulin is prohibited by its inability to acquire and maintain the native conformation. Previously, we have shown that disulfide-free immunoglobulins can be produced in Escherichia coli and purified from cytoplasmic extracts. RESULTS: Immunoglobulin REIv is the variable domain of a human kappa light chain. The disulfide-free variant REIv-C23V/Y32H was crystallized and its structure analyzed by X-ray crystallography (2.8 A resolution). The conformation of the variant is nearly identical to that of the wild-type protein and the conformationally stabilized variant REIv-T39K. This constitutes the first crystal structure of an immunoglobulin fragment without a disulfide bridge. The lack of the disulfide bridge produces no obvious local change in structure (compared with the wild type), whereas the Y32H mutation allows the formation of an additional hydrogen bond. There is a further change in the structure that is seen in the dimer in which Tyr49 has flipped out of the dimer interface in the mutant. CONCLUSIONS: Immunoglobulin derivatives without a central disulfide bridge but with stringently conserved wild-type conformation can be constructed in a practical two-step approach. First, the protein is endowed with additional folding stability by the introduction of one or more stabilizing amino acid exchanges; second, the disulfide bridge is destroyed by substitution of one of the two invariant cysteines. Such derivatives can be accumulated in soluble form in the cytoplasmic compartment of the E. coli cell. Higher protein yields and evolutionary refinement of catalytic antibodies by genetic complementation are among the possible advantages.

X-ray crystallography reveals stringent conservation of protein fold after removal of the only disulfide bridge from a stabilized immunoglobulin variable domain.,Uson I, Bes MT, Sheldrick GM, Schneider TR, Hartsch T, Fritz HJ Fold Des. 1997;2(6):357-61. PMID:9427009^[5]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Teng G, Papavasiliou FN. Immunoglobulin somatic hypermutation. Annu Rev Genet. 2007;41:107-20. PMID:17576170 doi:http://dx.doi.org/10.1146/annurev.genet.41.110306.130340
↑ Schroeder HW Jr, Cavacini L. Structure and function of immunoglobulins. J Allergy Clin Immunol. 2010 Feb;125(2 Suppl 2):S41-52. doi:, 10.1016/j.jaci.2009.09.046. PMID:20176268 doi:http://dx.doi.org/10.1016/j.jaci.2009.09.046
↑ McHeyzer-Williams M, Okitsu S, Wang N, McHeyzer-Williams L. Molecular programming of B cell memory. Nat Rev Immunol. 2011 Dec 9;12(1):24-34. doi: 10.1038/nri3128. PMID:22158414 doi:http://dx.doi.org/10.1038/nri3128
↑ Lefranc MP. Immunoglobulin and T Cell Receptor Genes: IMGT((R)) and the Birth and Rise of Immunoinformatics. Front Immunol. 2014 Feb 5;5:22. doi: 10.3389/fimmu.2014.00022. eCollection 2014. PMID:24600447 doi:http://dx.doi.org/10.3389/fimmu.2014.00022
↑ Uson I, Bes MT, Sheldrick GM, Schneider TR, Hartsch T, Fritz HJ. X-ray crystallography reveals stringent conservation of protein fold after removal of the only disulfide bridge from a stabilized immunoglobulin variable domain. Fold Des. 1997;2(6):357-61. PMID:9427009

1 Structural highlights
2 Function
3 Evolutionary Conservation
4 Publication Abstract from PubMed
5 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1ar2"

@@ Line 1: / Line 1: @@
 ==DISULFIDE-FREE IMMUNOGLOBULIN FRAGMENT==
-<StructureSection load='1ar2' size='340' side='right' caption='[[1ar2]], [[Resolution|resolution]] 2.80&Aring;' scene=''>
+<StructureSection load='1ar2' size='340' side='right'caption='[[1ar2]], [[Resolution|resolution]] 2.80&Aring;' scene=''>
 == Structural highlights ==
-<table><tr><td colspan='2'>[[1ar2]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AR2 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1AR2 FirstGlance]. <br>
+<table><tr><td colspan='2'>[[1ar2]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AR2 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1AR2 FirstGlance]. <br>
-</td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1ar2 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ar2 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1ar2 RCSB], [http://www.ebi.ac.uk/pdbsum/1ar2 PDBsum]</span></td></tr>
+</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.8&#8491;</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=1ar2 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ar2 OCA], [https://pdbe.org/1ar2 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ar2 RCSB], [https://www.ebi.ac.uk/pdbsum/1ar2 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ar2 ProSAT]</span></td></tr>
 </table>
+== Function ==
+[https://www.uniprot.org/uniprot/KVD33_HUMAN KVD33_HUMAN] V region of the variable domain of immunoglobulin light chains that participates in the antigen recognition (PubMed:24600447). Immunoglobulins, also known as antibodies, are membrane-bound or secreted glycoproteins produced by B lymphocytes. In the recognition phase of humoral immunity, the membrane-bound immunoglobulins serve as receptors which, upon binding of a specific antigen, trigger the clonal expansion and differentiation of B lymphocytes into immunoglobulins-secreting plasma cells. Secreted immunoglobulins mediate the effector phase of humoral immunity, which results in the elimination of bound antigens (PubMed:20176268, PubMed:22158414). The antigen binding site is formed by the variable domain of one heavy chain, together with that of its associated light chain. Thus, each immunoglobulin has two antigen binding sites with remarkable affinity for a particular antigen. The variable domains are assembled by a process called V-(D)-J rearrangement and can then be subjected to somatic hypermutations which, after exposure to antigen and selection, allow affinity maturation for a particular antigen (PubMed:20176268, PubMed:17576170).<ref>PMID:17576170</ref> <ref>PMID:20176268</ref> <ref>PMID:22158414</ref> <ref>PMID:24600447</ref>
 == Evolutionary Conservation ==
 [[Image:Consurf_key_small.gif|200px|right]]
 Check<jmol>
   <jmolCheckbox>
-    <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ar/1ar2_consurf.spt"</scriptWhenChecked>
+    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ar/1ar2_consurf.spt"</scriptWhenChecked>
     <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
     <text>to colour the structure by Evolutionary Conservation</text>
   </jmolCheckbox>
-</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf].
+</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1ar2 ConSurf].
 <div style="clear:both"></div>
 <div style="background-color:#fffaf0;">
@@ Line 23: / Line 27: @@
 From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
 </div>
+<div class="pdbe-citations 1ar2" style="background-color:#fffaf0;"></div>
 == References ==
 <references/>
@@ Line 28: / Line 33: @@
 </StructureSection>
 [[Category: Homo sapiens]]
-[[Category: Bes, M T]]
+[[Category: Large Structures]]
-[[Category: Fritz, H J]]
+[[Category: Bes MT]]
-[[Category: Hartsch, T]]
+[[Category: Fritz H-J]]
-[[Category: Schneider, T R]]
+[[Category: Hartsch T]]
-[[Category: Sheldrick, G M]]
+[[Category: Schneider TR]]
-[[Category: Uson, I]]
+[[Category: Sheldrick GM]]
-[[Category: Bence-jone]]
+[[Category: Uson I]]
-[[Category: Disulfide-free]]
-[[Category: Immunoglobulin]]
-[[Category: Immunoglobulin fragment]]

1ar2

From Proteopedia

Current revision

DISULFIDE-FREE IMMUNOGLOBULIN FRAGMENT

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

Personal tools

Navigation

Search

Toolbox