Anticoagulant mechanisms (Antithrombin and heparin, protein C and S, TFPI)

Question 1

Briefly outline the PC pathway

Answer 1

Thrombin-thrombomodulin complex activates PC

APC proteolytically inactivates FVa and FVIIIa thus inhibits thrombin generation.

Question 2

Describe the structure of PC

Answer 2

Protein C is a Vitamin K dependent serine protease zymogen which acts as an anticoagulant.
Contains a Gla domain which binds to PL, EPCR and PS

Question 3

Describe the structure of PS

Answer 3

Sex hormone-binding globulin domain (SHBG)
4x EGF-like domains: protein- protein interaction
Thrombin-sensitive region
Gla domain - highest sensitivity to PL in all vitamin K dependent proteinsn