Sandbox Reserved 1482: Difference between revisions

The calcium ion (Ca²⁺) and the copper ion (Cu²⁺) are both ligands the factor VIII is able to bind to <ref name="pdb" />. More precisely, in factor VIII there are two copper ions and their binding sites are located internally within the <scene name='80/802656/A3cu/1'>A3</scene> and the <scene name='80/802656/A1/1'>A1</scene> domain. The <scene name='80/802656/A1/1'>A1</scene> domain binds another ligand, a <scene name='80/802656/A1ca/1'>calcium ion</scene>, bound to its own binding site. <ref name="Ngo" />

 

One other molecule can be found on this protein: N-acetyl-D-glucosamine. They are covalently bound to Asn residus of the protein during the maturation process in the endoplasmic reticulum and the Golgi apparatus <ref name="Lenting">Lenting PJ, Pegon JN, Christophe OD, Denis CV. Factor VIII and von Willebrand factor – too sweet for their own good. Haemophilia. 2010 June; 16(Suppl. 5), 194–199. PMID: 20590881 doi: https://doi.org/10.1111/j.1365-2516.2010.02320.x</ref>. These molecules are not ligands since it is not a specific substrate that binds a specific site in the protein (). They are post-translational modifications and may be different depending on the physiological context ().The alpha-D-mannose molecule, present in the structure shown here, might also be a posttranslational modification (). Factor VIII is thus a glycoprotein ().