title: Identification and purification to near homogeneity of the vitamin K-dependent carboxylase.
abstract: Vitamin K-dependent carboxylase catalyzes the modification of specific glutamic acids to gamma-carboxyglutamic acid in several blood-coagulation proteins. This modification is required for the blood-clotting activity of these proteins and has thus been the subject of intense investigation. We have now identified the bovine vitamin K-dependent carboxylase and purified it to near homogeneity by an affinity procedure that uses the 59-amino acid peptide FIXQ/S (residues -18 to 41 of factor IX with mutations Arg----Gln at residue -4 and Arg----Ser at residue -1). The carboxylase as purified has a molecular weight of 94,000. It is also the major protein that can be cross-linked to iodinated FIXQ/S and is the only protein whose cross-linking is prevented by a synthetic factor IX propeptide. The degree of purification is about 7000-fold with reference to ammonium sulfate-fractionated microsomal protein from liver.
authors.affiliation: Department of Biology, University of North Carolina, Chapel Hill, NC 27599-3280.
authors.forename: S M
authors.initials: SM
authors.lastname: Wu
authors.forename: D P
authors.initials: DP
authors.lastname: Morris
authors.forename: D W
authors.initials: DW
authors.lastname: Stafford
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019735:Carbon-Carbon Ligases; D002417:Cattle; D002846:Chromatography, Affinity; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics; D008025:Ligases / Q000302:isolation & purification* / Q000378:metabolism; D008862:Microsomes, Liver / Q000201:enzymology*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010455:Peptides / Q000138:chemical synthesis
chemical_list: D010455:Peptides; D008025:Ligases; D019735:Carbon-Carbon Ligases; C020660:glutamyl carboxylase