Antithrombin

Function Antithrombin (AT) inactivates several enzymes of the coagulation cycle. AT is relatively inactive until it binds the heparan sidechains of the microvasculature. ▪ α-AT contains 4 occupied glycosylation sites and is found in blood palsma. ▪ β-AT contains only 3 occupied glycosylation sites. ▪ AT-I refers to the absorption of thrombin to fibrin. ▪ AT-II and heparin interfere with the interaction of thrombin and fibrinogen. ▪ AT-III inactivates thrombin in plasma. For details see Student Projects for UMass Chemistry 423 Spring 2012-7. ▪ AT-IV becomes activated during blood coagulation. See details for the antithrombin pentasaccharide complex in Molecular Playground/Antithrombin-Heparin. Disease AT deficiency diseases are: Acquired AT deficiency and Inherited AT deficiency. AT deficiency is involved in thrombosis and pulmonary embolism. Relevance AT activity is enhanced upon . Structural highlights The binding of AT to the heparans or the heparin drug is to a core pentasaccharide. The binding induces conformational change of AT. 3D structures of antithrombin Antithrombin 3D structures

spinqualitylabelsall models Glycosylated human antithrombin III complex with heparin (in green) (PDB code 3evj) Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image