Ch3

FIGURE 54-6 The vitamin K cycle: y-glutamyl carboxylation of vitamin K-dependent proteins. The enzyme ^-glutamyl carboxylase couples the oxidation of the reduced hydroquinone form (KH2) of vitamin Kx or K2, to )-carboxylation of Glu residues on vitamin K-dependent proteins, generating the epoxide of vitamin K (KO) and )-carboxyglutamate (Gla) residues in vitamin K-dependent precursor proteins in the endoplasmic reticulum. A 2,3-epoxide reductase regenerates vitamin KH2 and is the warfarin-sensitive step. The R on the vitamin K molecule represents a 20-carbon phytyl side chain in vitamin Kx and a 5- to 65-carbon prenyl side chain in vitamin K2.

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Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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