Factor IX: Difference between revisions

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'''-----This page is still under construction-------'''

~~{{STRUCTURE_2ypi| PDB=2ypi | SCENE= }}~~

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These mutations identified that residues 495-513 in the carboxylase act as an internal propeptide binding site (7).

== ''γ''-Carboxylation Reaction==

This reaction is catalyzed by the γ-glutamyl carboxylase in the ER and requires a reduced form of vitamin K, oxygen, and carbon dioxide. The reaction is initiated by the removal of a hydrogen atom at the γ position of glutamate. This reaction creates a carbon ion that reacts with carbon dioxide thus forming γ-carboxy glutamic acid. As the protein is carboxylated using carbon dioxide the reduced vitamin K (hydroquinone) is oxidized to epoxide. In order for this reaction to continue vitamin K must be regenerated, which is carried out by nicotinamide phosphate, thus allowing the continuation of the cycle. Protein carboxylation, provides a region which allows the protein to associate with the membrane anionic phospholipid surface, thus allowing close proximity to other components of coagulation. Without vitamin K, coagulation precursor proteins would circulate through the plasma, but would have minimal function.

[[Image:8707a900.gif|frame|left|''Vitamin K functions in the conversion of glutamic acid (Glu) in gamma-carboxyglutamate (Gla)''

Factor IX: Difference between revisions

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 '''-----This page is still under construction-------'''
-{{STRUCTURE_2ypi|  PDB=2ypi  |  SCENE=  }}
 <applet load='1lbg' size='380' frame='true' align='right' scene='Factor_IX/Ixstructure/2' />
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 These mutations identified that residues 495-513 in the carboxylase act as an internal propeptide binding site (7).
+== ''&gamma;''-Carboxylation Reaction==
+ This reaction is catalyzed by the γ-glutamyl carboxylase in the ER and requires a reduced form of vitamin K, oxygen, and carbon dioxide. The reaction is initiated by the removal of a hydrogen atom at the γ position of glutamate. This reaction creates a carbon ion that reacts with carbon dioxide thus forming γ-carboxy glutamic acid. As the protein is carboxylated using carbon dioxide the reduced vitamin K (hydroquinone) is oxidized to epoxide. In order for this reaction to continue vitamin K must be regenerated, which is carried out by nicotinamide phosphate, thus allowing the continuation of the cycle. Protein carboxylation, provides a region which allows the protein to associate with the membrane anionic phospholipid surface, thus allowing close proximity to other components of coagulation. Without vitamin K, coagulation precursor proteins would circulate through the plasma, but would have minimal function.
 [[Image:8707a900.gif|frame|left|''Vitamin K functions in the conversion of glutamic acid (Glu) in gamma-carboxyglutamate (Gla)''