A-Plasminogen activator

Urokinase (from human urine) [9039-53-6] Mr 53,000, [EC 3.4.21.31]. Crystn of this enzyme is induced at pH 5.0 to 5.3 (4") by careful addition of NaCl with gentle stirring until the soln becomes turbid (silky sheen). The NaCl concentration is increased gradually (over several days) until 98% of saturation is achieved whereby the urokinase crystallises as colourless thin brittle plates. It can be similarly recrystd to maximum specific activity [104K CTA units/mg of protein (Sherry et al. J Lab Clin Med 64 145 1964)]. [Lesuk et al. Science 147 880 1965 NMR Bogusky et al. Biochemistry 28 6728 1989.] It is a plasminogen activator [Gold et al. Biochem J 262 1989 ]. 

Levin E. G., Santell L. Association of a plasminogen activator inhibitor (PAI-1) with the growth substratum and membrane of human endothelial cells. J Cell Biol 1987 105, 2543-9. 

Mechanism of Action A synthetic pituitary hormone that increases reabsorption of water by increasing permeability of collecting ducts of the kidneys. Also serves as a plasminogen activator. Therapeutic Effect Increases plasma factor Vlll (antihemo-philicfactor). Decreases urinary output. 

Streptokinase and plasminogen form a complex having the characteristics of a plasminogen activator and activating plasminogen molecules not yet combined with streptokinase to plasmin. The concept of acylation of fibrinolytic enzymes... 

Only one fibrinolytic agent has been recommended in the United Kingdom for treatment of acute stroke alteplase, a plasminogen activator. This is used only under specialist supervision as there is a significant risk of intracranial haemorrhage. 

Teernstra OP, Evers SM, Fodder J et al. (2003). Stereotactic treatment of intracerebral hematoma by means of a plasminogen activator a multicenter randomized controlled trial (SICHPA). Stroke 34 968-974... 

An important application of fibrinolytic drugs has been to dissolve thrombi in acutely occluded coronary arteries, thereby to restore blood supply to ischaemic myocardium, to limit necrosis and to improve prognosis. The approach is to give a plasminogen activator intravenously by infusion or by bolus injection in order to increase the formation of the fibrinolytic enzyme plasmin. Those currently available include ... 

Chapman, H.A., Plasminogen activators, in-tegrins, and the coordinated regulation of cell... 

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