View source for 6vca


==TB38 complex==
<StructureSection load='6vca' size='340' side='right'caption='[[6vca]], [[Resolution|resolution]] 3.73&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6vca]] is a 12 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=6VCA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6VCA FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 3.73&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BMA:BETA-D-MANNOSE'>BMA</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></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=6vca FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6vca OCA], [https://pdbe.org/6vca PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6vca RCSB], [https://www.ebi.ac.uk/pdbsum/6vca PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6vca ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/5NTD_HUMAN 5NTD_HUMAN] Hereditary arterial and articular multiple calcification syndrome. The disease is caused by mutations affecting the gene represented in this entry.
== Function ==
[https://www.uniprot.org/uniprot/5NTD_HUMAN 5NTD_HUMAN] Hydrolyzes extracellular nucleotides into membrane permeable nucleosides. Exhibits AMP-, NAD-, and NMN-nucleosidase activities.<ref>PMID:21933152</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The dimeric ectonucleotidase CD73 catalyzes the hydrolysis of AMP at the cell surface to form adenosine, a potent suppressor of the immune response. Blocking CD73 activity in the tumor microenvironment can have a beneficial effect on tumor eradication and is a promising approach for cancer therapy. Biparatopic antibodies binding different regions of CD73 may be a means to antagonize its enzymatic activity. A panel of biparatopic antibodies representing the pairwise combination of 11 parental monoclonal antibodies against CD73 was generated by Fab-arm exchange. Nine variants vastly exceeded the potency of their parental antibodies with &gt;/=90% inhibition of activity and subnanomolar EC(50) values. Pairing the Fabs of parents with nonoverlapping epitopes was both sufficient and necessary whereas monovalent antibodies were poor inhibitors. Some parental antibodies yielded potent biparatopics with multiple partners, one of which (TB19) producing the most potent. The structure of the TB19 Fab with CD73 reveals that it blocks alignment of the N- and C-terminal CD73 domains necessary for catalysis. A separate structure of CD73 with a Fab (TB38) which complements TB19 in a particularly potent biparatopic shows its binding to a nonoverlapping site on the CD73 N-terminal domain. Structural modeling demonstrates a TB19/TB38 biparatopic antibody would be unable to bind the CD73 dimer in a bivalent manner, implicating crosslinking of separate CD73 dimers in its mechanism of action. This ability of a biparatopic antibody to both crosslink CD73 dimers and fix them in an inactive conformation thus represents a highly effective mechanism for the inhibition of CD73 activity.

A highly potent CD73 biparatopic antibody blocks organization of the enzyme active site through dual mechanisms.,Stefano JE, Lord DM, Zhou Y, Jaworski J, Hopke J, Travaline T, Zhang N, Wong K, Lennon A, He T, Bric-Furlong E, Cherrie C, Magnay T, Remy E, Brondyk W, Qiu H, Radosevic K J Biol Chem. 2020 Dec 25;295(52):18379-18389. doi: 10.1074/jbc.RA120.012395. Epub , 2020 Oct 29. PMID:33122192<ref>PMID:33122192</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6vca" style="background-color:#fffaf0;"></div>

==See Also==
*[[Antibody 3D structures|Antibody 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Lord DM]]
[[Category: Zhou YF]]