Vitamin K Antagonist

Question 1

The commonly used vitamin K antagonist is ________. This is a ________ (found in plants) derivative. It also inhibits γ-carboxylation.

Answer 1

warfarin; coumarin

Question 2

The four vitamin K-dependent coagulation factors II, VII, IX and X
undergo post-translational _________ to enable them to bind _______ and to localize enzymatic processes

Answer 2

γ-carboxylation; calcium

Question 3

Protein C and protein S (the _______ of blood coagulation) also undergo γ-carboxylation and vitamin K antagonists prevent their activity by inhibiting the process

Answer 3

inhibitors;

Question 4

________& is a vitamin K-dependent
protein.
it regulates clotting by inactivating
______ & _______.

The gene for protein C is located on
chromosome _____.
It is activated by _________

Answer 4

Protein C; Va and VIIIa,
2, thrombomodulin

Question 5

_________ acts as a cofactor for protein C. It forms a complex with protein C that inactivates Va and VIIIa. It has also its independent anticoagulant activity by virtue of its ability to compete with factor Xa for binding with factor Va

Answer 5

Protein S

Question 6

Function of ________ is similar to
that of protein S.

Answer 6

protein Z