Factor IX: Difference between revisions

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The Gla domain perhaps also interacts with factor VIIIa via Mg2+-binding sites. Membrane bound FIXa forms an arched structure which is seen in the spatial relationship among the Gla, epidermal growth factor, and serine protease domains. This arched allows for the formation of a concave surface on the right side of FIXa  and acts as a binding site for factor VIIIa. The Mg-8 ion points toward this concave surface making it ideal in the interaction between FIXa and GVIIIa. Similarly, [[Mg-8 may contribute to the binding to factors VIIa and X]].
The Gla domain perhaps also interacts with factor VIIIa via Mg2+-binding sites. Membrane bound FIXa forms an arched structure which is seen in the spatial relationship among the Gla, epidermal growth factor, and serine protease domains. This arched allows for the formation of a concave surface on the right side of FIXa  and acts as a binding site for factor VIIIa. The Mg-8 ion points toward this concave surface making it ideal in the interaction between FIXa and GVIIIa. Similarly, [[Mg-8 may contribute to the binding to factors VIIa and X]].


Bovine <scene name='Factor_IX/Gladomain/1'>Factor IX -(1-46)</scene> bound to a snake venom protein (Factor IX-bp), is crystallized in the presence of calcium and magnesium ions and in the presence of calcium alone.  
Bovine <scene name='Factor_IX/Gladomain/1'>Factor IX -(1-46)</scene> bound to a snake venom protein (Factor IX-bp), is crystallized in the presence of calcium and magnesium ions and in the presence of calcium alone<ref>PMID:12695512</ref>.  


This structure emphasizes the possible role of magnesium in Gla domain binding to membrane surfaces. However upon examination of the calcium bound Factor IX-(1-46) complex revealed that the calcium coordination within this FIX Gla domain structure differes from other vitamin K-dependent proteins (prothrombin (7), Factor VII (10), and Factor X (11)). This deviation may be explained by the interaction of the snake venom FIX-bp interaction (this reference).  
This structure emphasizes the possible role of magnesium in Gla domain binding to membrane surfaces. However upon examination of the calcium bound Factor IX-(1-46) complex revealed that the calcium coordination within this FIX Gla domain structure differs from other vitamin K-dependent proteins (prothrombin, Factor VII, and Factor X). This deviation may be explained by the interaction of the snake venom FIX-bp interaction.  
{{STRUCTURE_1nl0|  PDB=1nl0  |  SCENE=  }}  
{{STRUCTURE_1nl0|  PDB=1nl0  |  SCENE=  }}  
To further probe into the structure of FIX Gla domain, [[conformation-specific anti-Factor IX antibodies]] were utilized. Using an  
To further probe into the structure of FIX Gla domain, [[conformation-specific anti-Factor IX antibodies]] were utilized. Using an