1s18: Difference between revisions

[[Image:1s18.gif|left|200px]]<br /><applet load="1s18" size="350" color="white" frame="true" align="right" spinBox="true"  

Hematophagous arthropods secrete a salivary apyrase that inhibits platelet activation by catabolizing ADP released from damaged tissues and blood cells. We report the X-ray crystal structures of a human enzyme of the soluble apyrase family in its apo state and bound to a substrate analog. The structures reveal a nucleotide binding domain comprising a five-blade beta propeller, binding determinants of the substrate and the active site, and an unusual calcium binding site with a potential regulatory function. Using a comparative structural biology approach, we were able to redesign the human apyrase so as to enhance its ADPase activity by more than 100-fold. The engineered enzyme is a potent inhibitor of platelet aggregation and may serve as the basis for the development of a new class of antithrombotic agents.

1S18 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=CA:'>CA</scene>, <scene name='pdbligand=ACT:'>ACT</scene> and <scene name='pdbligand=TRS:'>TRS</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Apyrase Apyrase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.6.1.5 3.6.1.5] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1S18 OCA].  

[[Category: Smith, T M.]]

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