TAILIEUCHUNG - Báo cáo Y học: Expression and characterization of recombinant vitamin K-dependent c-glutamyl carboxylase from an invertebrate, Conus textile

Themarine snailConusis the sole invertebratewherein both the vitamin K-dependent carboxylase and its product, c-carboxyglutamic acid, have been identified. To examine its biosynthesis of c-carboxyglutamic acid, we studied the carboxylase from Conusvenom ducts. The carboxylase cDNA fromConus textilehas an ORF that encodes a 811-amino-acid proteinwhich exhibits sequence similarity to the vertebrate carboxylases, with 41% identity and 60% sequence similarity to the bovine carboxylase. | Eur. J. Biochem. 269 6162-6172 2002 FEBS 2002 doi Expression and characterization of recombinant vitamin K-dependent c-glutamyl carboxylase from an invertebrate Conus textile Eva Czerwiec1 Gail S. Begley1 Mila Bronstein2 Johan Stenflo1 3 Kevin Taylor1 Barbara C. Furie1 2 and Bruce Furie1 2 1Marine Biological Laboratory Woods Hole MA USA 2Center for Hemostasis and Thrombosis Research Beth Israel Deaconess Medical Center and Harvard Medical School Boston MA USA 3Department of Clinical Chemistry Lund University University Hospital Malmo Sweden The marine snail Conus is the sole invertebrate wherein both the vitamin K-dependent carboxylase and its product y-carboxyglutamic acid have been identified. To examine its biosynthesis of y-carboxyglutamic acid we studied the carboxylase from Conus venom ducts. The carboxylase cDNA from Conus textile has an ORF that encodes a 811-amino-acid protein which exhibits sequence similarity to the vertebrate carboxylases with 41 identity and w 60 sequence similarity to the bovine carboxylase. Expression of this cDNA in COS cells or insect cells yielded vitamin K-dependent carboxylase activity and vitamin K-dependent epoxidase activity. The recombinant carboxylase hasamolecularmassof w 130 kDa. The recombinant Conus carboxylase carboxylated Phe-Leu-Glu-Glu-Leu and the 28-residue peptides based on residues -18 to 10 of human proprothrombin and proFactor IX with Km values of 420 M M and 6 M respectively the Km for vitamin K is 52 M. The Km values for peptides based on the sequence of the conotoxin e-TxIX and two precursor analogs containing 12 or 29 amino acids of the propeptide region are 565 IM 75 M and 74 IM respectively. The recombinant Conus carboxylase in the absence of endogenous substrates is stimulated up to fivefold by vertebrate propeptides but not by Conus propeptides. These results suggest two propeptide-binding sites in the carboxylase one that binds the Conus and vertebrate propeptides .

• Báo cáo khoa học
• Report medicine
• traditional medicine
• scientific reports
• Structural biochemistry
• bacteria
• chemical reaction
• medical knowledge
• medical research
• analysis of cytoplasmic
• oxidation
• Crystal structure
• hemoglobin
• medicine
• cell proliferation
• breast cancer
• gastric cancer
• hormone medicine
• tumor cells
• biochemical studies
• environmental medicine