1ae8 | pdb_00001ae8
HUMAN ALPHA-THROMBIN INHIBITION BY EOC-D-PHE-PRO-AZALYS-ONP
Structural highlights
Disease[THRB_HUMAN] Defects in F2 are the cause of factor II deficiency (FA2D) [MIM:613679]. It is a very rare blood coagulation disorder characterized by mucocutaneous bleeding symptoms. The severity of the bleeding manifestations correlates with blood factor II levels.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] Genetic variations in F2 may be a cause of susceptibility to ischemic stroke (ISCHSTR) [MIM:601367]; also known as cerebrovascular accident or cerebral infarction. A stroke is an acute neurologic event leading to death of neural tissue of the brain and resulting in loss of motor, sensory and/or cognitive function. Ischemic strokes, resulting from vascular occlusion, is considered to be a highly complex disease consisting of a group of heterogeneous disorders with multiple genetic and environmental risk factors.[13] Defects in F2 are the cause of thrombophilia due to thrombin defect (THPH1) [MIM:188050]. It is a multifactorial disorder of hemostasis characterized by abnormal platelet aggregation in response to various agents and recurrent thrombi formation. Note=A common genetic variation in the 3-prime untranslated region of the prothrombin gene is associated with elevated plasma prothrombin levels and an increased risk of venous thrombosis. Defects in F2 are associated with susceptibility to pregnancy loss, recurrent, type 2 (RPRGL2) [MIM:614390]. A common complication of pregnancy, resulting in spontaneous abortion before the fetus has reached viability. The term includes all miscarriages from the time of conception until 24 weeks of gestation. Recurrent pregnancy loss is defined as 3 or more consecutive spontaneous abortions.[14] Function[THRB_HUMAN] Thrombin, which cleaves bonds after Arg and Lys, converts fibrinogen to fibrin and activates factors V, VII, VIII, XIII, and, in complex with thrombomodulin, protein C. Functions in blood homeostasis, inflammation and wound healing.[15] [HIRV1_HIRME] Hirudin is a potent thrombin-specific protease inhibitor. It forms a stable non-covalent complex with alpha-thrombin, thereby abolishing its ability to cleave fibrinogen.[16] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedKinetics, thermodynamics and structural aspects of human alpha-thrombin (thrombin) inhibition by newly synthesized low molecular weight derivatives of alpha-azalysine have been investigated. The thrombin catalyzed hydrolysis of N-ethoxycarbonyl-D-Phe-Pro-alpha-azaLys p-nitrophenyl ester (Eoc-D-Phe-Pro-azaLys-ONp) and N-carbobenzoxy-Pro-alpha-azaLys p-nitrophenyl ester (Cbz-Pro-azaLys-ONp) was investigated at pH 6.2 and 21.0 degrees C, and analyzed in parallel with that of N-alpha-(N,N-dimethylcarbamoyl)-alpha-azalysine p-nitrophenyl ester (Dmc-azaLys-ONp). Decarboxylation following the enzymatic hydrolysis of these p-nitrophenyl esters gave the corresponding 1-peptidyl-2(4-aminobutyl) hydrazines (peptidyl-Abh) showing properties of thrombin competitive inhibitors. Therefore, thermodynamics for the reversible binding of D-Phe-Pro-Abh, Cbz-Pro-Abh and Dmc-Abh to thrombin was examined. These results are consistent with the minimum four-step catalytic mechanism for product inhibition of serine proteinases. Eoc-D-Phe-Pro-azaLys-ONp and Eoc-D-Phe-Pro-Abh display a sub-micromolar affinity for thrombin together with a high selectivity versus homologous plasmatic and pancreatic serine proteinases acting on cationic substrates. The three-dimensional structures of the reversible non-covalent thrombin:Eoc-D-Phe-Pro-Abh and thrombin:Cbz-Pro-Abh complexes have been determined by X-ray crystallography at 2.0 A resolution (R-factor = 0.169 and 0.179, respectively), and analyzed in parallel with that of the thrombin:Dmc-azaLys acyl-enzyme adduct. Both Eoc-D-Phe-Pro-Abh and Cbz-Pro-Abh competitive inhibitors are accommodated in the thrombin active center, spanning the region between the aryl binding site and the S1 primary specificity subsite. Human alpha-thrombin inhibition by the highly selective compounds N-ethoxycarbonyl-D-Phe-Pro-alpha-azaLys p-nitrophenyl ester and N-carbobenzoxy-Pro-alpha-azaLys p-nitrophenyl ester: a kinetic, thermodynamic and X-ray crystallographic study.,De Simone G, Balliano G, Milla P, Gallina C, Giordano C, Tarricone C, Rizzi M, Bolognesi M, Ascenzi P J Mol Biol. 1997 Jun 20;269(4):558-69. PMID:9217260[17] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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