A hetero-dimer model for concerted action of vitamin K carboxylase and vitamin K reductase in vitamin K cycle

作者：Wu Sangwook; Liu Shubin; Davis Charles H; Stafford Darrel W; Kulman John D; Pedersen Lee G^*

来源：Journal of Theoretical Biology, 2011, 279(1): 143-149.

DOI：10.1016/j.jtbi.2011.03.030

• Vitamin K cycle
• Vitamin K carboxylase
• Vitamin K epoxide reductase
• Hetero-dimer

Vitamin K carboxylase (VKC) is believed to convert vitamin K, in the vitamin K cycle, to an alkoxide-epoxide form which then reacts with CO(2) and glutamate to generate gamma-carboxyglutamic acid (Gla). Subsequently, vitamin K epoxide reductase (VKOR) is thought to convert the alkoxide-epoxide to a hydroquinone form. By recycling vitamin K, the two integral-membrane proteins, VKC and VKOR, maintain vitamin K levels and sustain the blood coagulation cascade. Unfortunately, NMR or X-ray crystal structures of the two proteins have not been characterized. Thus, our understanding of the vitamin K cycle is only partial at the molecular level. In this study, based on prior biochemical experiments on VKC and VKOR, we propose a hetero-dimeric form of VKC and VKOR that may explain the efficient oxidation and reduction of vitamin K during the vitamin K cycle.

• 出版日期2011-6-21