منابع مشابه
The vitamin K-dependent carboxylase.
The only known biological function of Vitamin K (Fig. 1) in animals is as a required cofactor for the production of the unusual amino acid, -carboxyglutamate (Gla). This amino acid has a profound role in human blood coagulation. Several blood proteins require the presence of nine to thirteen Gla residues for normal function; these are the socalled Vitamin K-dependent (VKD) proteins. While some ...
متن کاملVitamin K-dependent carboxylation of the carboxylase.
Vitamin K-dependent (VKD) proteins require modification by the VKD-gamma-glutamyl carboxylase, an enzyme that converts clusters of glus to glas in a reaction that requires vitamin K hydroquinone, for their activity. We have discovered that the carboxylase also carboxylates itself in a reaction dependent on vitamin K. When pure human recombinant carboxylase was incubated in vitro with 14CO2 and ...
متن کاملThe inhibition of vitamin K-dependent carboxylase by cyanide.
The formation of 7-carboxyglutamic acid residues from glutamic acid residues is a vitamin K-dependent carboxylation reaction. The reaction has been demonstrated in various species and tissues [1,2], but the most extensive studies have been performed in the microsomal fraction of rat liver.It is generally assumed that the carboxylation reaction is coupled to the epoxidation of reduced vitamin K ...
متن کاملy-Carboxyglutamate-containing proteins and the vitamin K-dependent carboxylase
Vitamin K functions as a cofactor during the posttranslational modification of proteins. The reaction in question is the carboxylation of glutamate (Glu) residues into y-carboxyglutamate (Gla) and it is depicted in Fig. 1. Because Glu is only a weak Ca2l chelator and Gla a much stronger one, the vitamin K-dependent step substantially increases the Ca2"-binding capacity ofa protein. The discover...
متن کاملBiosynthesis of Prothrombin: Intracellular Localization of the Vitamin K-Dependent Carboxylase and the Sites
Prothrombin is a vitamin K-dependent blood coagulation protein that undergoes posttranslational y-carboxylation and propeptide cleavage during biosynthesis. The propeptide contains the y-carboxylation recognition site that directs y-carboxylation. To identify the intracellular sites of carboxylation and propeptide cleavage, we monitored the synthesis of prothrombin in Chinese hamster ovary cell...
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ژورنال
عنوان ژورنال: The Journal of Nutrition
سال: 2000
ISSN: 0022-3166,1541-6100
DOI: 10.1093/jn/130.8.1877