Vitamin K-Dependent Carboxylase: Growth to Maturity

摘要

During maturation, most secretory proteins undergo extensive post-translational processing before they are secreted into the extracellular environment. One of these post-translational modifications is the conversion of glutamate (Glu) into gamma-carboxyglutamate (Gla) residues. In Chapter 1 of the thesis a review is presented of current knowledge concerning the gamma-glutamylcarboxylation reaction and the role of vitamin K in this reaction. In Chapter 2 the preparation and sensitivity of reagents are described. Secondly an improved method for the separation and detection of descarboxy and normal coagulation factors by high performance liquid chromatography (HPLC) is reported. In Chapter 3 the optimizing of an in vitro system for measuring vitamin K dependent carboxylation is described. Chapter 4 focuses attention on the cofactor of carboxylase: vitamin K. In Chapter 5 some aspects of the reductases involved in the recycling of vitamin K are investigated. In Chapter 6 data concerning substrates in the vitamin K-dependent carboxylase reaction are described.