Inhibitors of 2-Ketoglutarate-dependent Dioxygenases Block Aspartyl β-Hydroxylation of Recombinant Human Factor IX in Several Mammalian Expression Systems

摘要: Abstract While a role has been ascribed to the gamma-carboxyglutamate (Gla) residues in vitamin K-dependent coagulation proteins and enzyme catalyzing this posttranslational modification identified partially characterized, both functional significance of second posttranslationally synthesized amino acid found these proteins, beta-hydroxyaspartate (Hya), aspartyl beta-hydroxylating remain be determined. We now report that inhibitors 2-ketoglutarate-dependent dioxygenases, such as dipyridyl, o-phenanthroline, pyridine 2,4-dicarboxylate, block hydroxylation Asp64 recombinant factor IX molecules produced three different mammalian expression systems. This was not inhibited by specific copper chelators 2,9-dimethylphenanthroline or D-penicillamine. The Gla levels were unaffected compounds demonstrate carboxylation proceeds independently hydroxylation. Using Hya-deficient we residue does play significant binding endothelial cells under equilibrium conditions. From additional studies have concluded domain is major cell IX. Furthermore, contrast demonstrating marked loss one-stage clotting activity factors following site-directed mutations neutral basic (Rees, D. J. G., Jones, I. M., Handford, P. A., Walter, S. J., Esnouf, M. P., Smith, K. Brownlee, G. (1988) EMBO 7, 2053-2061), decrease with manner may prove more appropriate elucidate function Hya than those mutagenesis.