Protein C, also known as autoprothrombin IIA and blood coagulation factor XIV,

Physiology

The activation of protein&nbsp;C is strongly promoted by thrombomodulin and endothelial protein&nbsp;C receptor (EPCR), the latter of which is found primarily on endothelial cells (cells on the inside of blood vessels). The presence of thrombomodulin accelerates activation by several orders of magnitude, Activated protein&nbsp;C resistance occurs when APC is unable to perform its functions. This disease has similar symptoms to protein&nbsp;C deficiency. The most common mutation leading to activated protein&nbsp;C resistance among Caucasians is at the cleavage site in Factor V for APC. There, Arg<sup>506</sup> is replaced with Gln, producing Factor V Leiden. This mutation is also called a R506Q.

Role in medicine

In November 2001, the Food and Drug Administration approved Drotrecogin alfa-activated (DrotAA) for the clinical treatment of adults suffering from severe sepsis and with a high risk of death. In October 2011 rhAPC (Xigris) was withdrawn from the market by Eli Lilly due to a higher mortality in a trial among adults. Ceprotin is indicated in purpura fulminans and coumarin-induced skin necrosis in people with severe congenital protein C deficiency.

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  • The MEROPS online database for peptidases and their inhibitors: S01.218