Identification of Phospholipid as an Essential K - dependent Carboxylase * Part of Bovine Vitamin
نویسنده
چکیده
Vitamin K-dependent carboxylase from bovine liver contains phospholipid (primarily phosphatidylcholine), which is essential for its in vitro activity. Sepharosebound carboxylase can be depleted of phospholipids, either by washing the enzyme with detergents or by phospholipase treatment. The enzyme can be reconstituted by adding mixed micelles of phosphatidylcholine and cholate to the Sepharose-bound proteins.
منابع مشابه
Expression of bovine vitamin K-dependent carboxylase activity in baculovirus-infected insect cells.
A vitamin K-dependent carboxylase has recently been purified from bovine liver microsomes and candidate cDNA clones have been isolated. Definitive identification of the carboxylase remains circumstantial since expression of candidate carboxylase cDNAs in mammalian cells is confounded by the presence of endogenous carboxylase activity. To overcome this problem, a recombinant strain of baculoviru...
متن کاملVitamin K-dependent carboxylase: affinity purification from bovine liver by using a synthetic propeptide containing the gamma-carboxylation recognition site.
The vitamin K-dependent carboxylase catalyzes the posttranslational modification of specific glutamic acid residues to form gamma-carboxyglutamic acid residues within the vitamin K-dependent proteins. This enzyme recognizes the gamma-carboxylation recognition site on the propeptide of the precursor forms of the vitamin K-dependent blood coagulation proteins. To purify this enzyme to homogeneity...
متن کاملIsolation and partial characterization of a vitamin K-dependent carboxylase from bovine aortae.
Vitamin K-dependent carboxylase activity has been demonstrated in the crude microsomal fraction of the intima of bovine aortae. The procedure for the isolation of vessel wall carboxylase is a slight modification of the general preparation procedure for tissue microsomes. The highest activity of the non-hepatic enzyme was observed at 25 degrees C and hardly any NADH-dependent vitamin K reductase...
متن کاملIn vitro and in vivo functional characterization of bovine vitamin K-dependent gamma-carboxylase expressed in Chinese hamster ovary cells.
Coagulation factor IX is a serine protease for which high-level expression of biologically active protein in heterologous cells is limited due to inefficient proteolytic removal of the propeptide as well as vitamin K-dependent carboxylation of multiple amino-terminal glutamic acid residues. We have overexpressed the vitamin K-dependent gamma-carboxylase cDNA and monitored its ability to improve...
متن کاملVitamin K - Dependent Biosynthesis of g - Carboxyglutamic Acid
VITAMIN K, AN ESSENTIAL vitamin, is a cofactor for a single known enzymatic reaction: the conversion of glutamic acid to g-carboxyglutamic acid in vitamin K-dependent proteins during their biosynthesis. Since the discovery of vitamin K and its association with blood coagulation,1 many milestones have been passed on the road to understanding the biological role of vitamin K. Important early land...
متن کامل