Antithrombin: in control of coagulation.
Antithrombin is a serine proteinase inhibitor (serpin) which controls the process of coagulation. It has a well defined structure, consisting of three beta-sheets, nine alpha-helices and a reactive centre loop (RCL). The RCL contains the reactive centre which harbours a bait sequence for target proteases; cleavage results in inhibition by a unique mechanism. The inhibitory activity of antithrombin is controlled by its interaction with the co-factor, heparin, which accelerates its interaction with target proteases. This ensures that heparin and its newer derivatives, such as heparin pentasaccharide, are the mainstay therapeutics for control of thrombosis or inappropriate clotting. The clinical importance of antithrombin is manifested by its clear association with thrombosis when deficiency states occur.
Quinsey
Noelene S
NS
Department of Biochemistry & Molecular Biology, Monash University, Clayton, Vic. 3800, Australia.
Greedy
Ainslie L
AL
Bottomley
Stephen P
SP
Whisstock
James C
JC
Pike
Robert N
RN
D000818:Animals; D000990:Antithrombin III / Q000737:chemistry / Q000378:metabolism*; D020152:Antithrombin III Deficiency / Q000235:genetics / Q000378:metabolism; D001777:Blood Coagulation; D006493:Heparin / Q000378:metabolism; D006801:Humans; D011487:Protein Conformation; D015842:Serine Proteinase Inhibitors / Q000378:metabolism*; D013927:Thrombosis / Q000209:etiology
D015842:Serine Proteinase Inhibitors; D000990:Antithrombin III; D006493:Heparin