The catalytic mechanism of vitamin K epoxide reduction in a cellular environment.

Vitamin K epoxide reductases (VKORs) constitute a major family of integral membrane thiol oxidoreductases. In humans, VKOR sustains blood coagulation and bone mineralization through the vitamin K cycle. Previous chemical models assumed that the catalysis of human VKOR (hVKOR) starts from a fully reduced active site.

[Development of a cell-based diagnostic system for vitamin K-dependent coagulation factor deficiency 1].

Objective: To develop a cell-based system for the diagnosis of vitamin K-dependent coagulation factor deficiency 1 (VKCFD1).

Methods: In HEK293 cells stably expressing the reporter gene FIX-Gla-PC, the gamma-glutamyl carboxylase (GGCX) gene was knocked out by using CRISPR/Cas9 technology. Enzyme-linked immunosorbent assay (ELISA), DNA sequencing and Western blotting were used to identify the GGCX gene knockout cells.