protein C

noun

: a vitamin K-dependent glycoprotein that in its activated form is involved in preventing blood clot formation through the proteolytic inactivation of factors V and VIII and that plays a role in inhibiting inflammation, promoting endothelial cell apoptosis, and maintaining permeability of blood vessel walls

The activated protein C system is one of the hemostatic checks and balances that inhibit coagulation.

—Jan P. Vandenbroucke et al.

Note: A deficiency of protein C is associated with an increased risk of venous thrombosis.

see protein s

Word History

Etymology

so named because it was third ("Pool C") in a group of four proteins eluted from bovine plasma by means of a chromatograph

Note: The name was introduced by the Swedish chemist Johann Stenflo (born 1940) in "A New Vitamin K-dependent Protein: Purification from Bovine Plasma and Preliminary Characterization," Journal of Biological Chemistry, vol. 251, no. 2 (January 25, 1976), pp. 355-363.

First Known Use

1976, in the meaning defined above

Medical Definition

protein C

noun

: a vitamin K-dependent glycoprotein that in its activated form is involved in preventing blood clot formation through the proteolytic inactivation of factor V and factor VIII and that plays a role in inhibiting inflammation, promoting endothelial cell apoptosis, and maintaining permeability of blood vessel walls

Note: A deficiency of protein C is associated with an increased risk of venous thrombosis.

see apc, protein S