What is the primary mechanism by which antithrombin III inhibits coagulation factor activity?

A Binding to phospholipid surfaces
B Competitive inhibition of factor activation
C Covalent binding to factor active sites ✓
D Non-competitive allosteric inhibition

Explanation

Antithrombin III inhibits coagulation factors by covalently binding to their active sites, thereby preventing them from interacting with their substrates.

Source

Guyton and Hall Textbook of Medical Physiology
Hematology Hematology: Coagulation Disorders Hematology: Coagulation Disorders Medium MEDICAL Confidence: high