Dermatan sulfate cofactor activation

Heparin cofactor II is a second plasma SERPIN which has resemblance to antithrombin in that it is activatable by glycosaminoglycan binding. This protein has also been called antithrombin BM, dermatan sulfate cofactor, and human leuserpin 2 (88). The existence of this second inhibitor and heparin cofactor was first shown by Briginshaw in 1974 (89). Whereas antithrombin is observed to have progressive antithrombin activity and to also inhibit factor Xa, the second... 

Heparin cofactor II, when activated by binding to glycosaminoglycans (dermatan sulfate, heparins, and heparin), inhibits thrombin (24). The 43-kDa serpin, proteinase nexin 1, possesses 30% sequence homology with ATIII and can be activated by binding to heparin to inhibit several serine proteinases including thrombin (25). Proteinase nexin 2 is found within the platelet a-granule and is released when platelets are activated (26). It is able to inhibit factor XIa. 

Thrombin and factor Xa that have escaped into the blood flow are both inhibited by serpins, anti-thrombin III (ATIII) and heparin cofactor II (HCII). These proteins bind to heparin sulfate or dermatan sulfate (Sect. 6.3.1), glycosaminoglycans which are secreted onto the luminal surface of healthy endothelial cells and also released into the blood from mast cells activated by an injury. Among the heparin molecules is a pentaglycan sequence... 

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