| 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] [TRBM_HUMAN] Defects in THBD are the cause of thrombophilia due to thrombomodulin defect (THPH12) [MIM:614486]. A hemostatic disorder characterized by a tendency to thrombosis.[15] [16] [17] Defects in THBD are a cause of susceptibility to hemolytic uremic syndrome atypical type 6 (AHUS6) [MIM:612926]. An atypical form of hemolytic uremic syndrome. It is a complex genetic disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, renal failure and absence of episodes of enterocolitis and diarrhea. In contrast to typical hemolytic uremic syndrome, atypical forms have a poorer prognosis, with higher death rates and frequent progression to end-stage renal disease. Note=Susceptibility to the development of atypical hemolytic uremic syndrome can be conferred by mutations in various components of or regulatory factors in the complement cascade system. Other genes may play a role in modifying the phenotype.[18] [19]
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.[20] [TRBM_HUMAN] Thrombomodulin is a specific endothelial cell receptor that forms a 1:1 stoichiometric complex with thrombin. This complex is responsible for the conversion of protein C to the activated protein C (protein Ca). Once evolved, protein Ca scissions the activated cofactors of the coagulation mechanism, factor Va and factor VIIIa, and thereby reduces the amount of thrombin generated.
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 PubMed
BACKGROUND: Coagulation is a highly regulated process where the ability to prevent blood loss after injury is balanced against the maintenance of blood fluidity. Thrombin is at the center of this balancing act. It is the critical enzyme for producing and stabilizing a clot, but when complexed with thrombomodulin (TM) it is converted to a powerful anticoagulant. Another cofactor that may play a role in determining thrombin function is the monovalent cation Na(+). Its apparent affinity suggests that half of the thrombin generated is in a Na(+)-free 'slow' state and half is in a Na(+)-coordinated 'fast' state. While slow thrombin is a poor procoagulant enzyme, when complexed to TM it is an effective anticoagulant. METHODS: To better understand this molecular transformation we solved a 2.4 A structure of thrombin complexed with EGF domains 4-6 of TM in the absence of Na(+) and other cofactors or inhibitors. RESULTS: We find that TM binds as previously observed, and that the thrombin component resembles structures of the fast form. The Na(+) binding loop is observed in a conformation identical to the Na(+)-bound form, with conserved water molecules compensating for the missing ion. Using the fluorescent probe p-aminobenzamidine we show that activation of slow thrombin by TM principally involves the opening of the primary specificity pocket. CONCLUSIONS: These data show that TM binding alters the conformation of thrombin in a similar manner as Na(+) coordination, resulting in an ordering of the Na(+) binding loop and an opening of the adjacent S1 pocket. We conclude that other, more subtle subsite changes are unlikely to influence thrombin specificity toward macromolecular substrates.
Molecular basis of thrombomodulin activation of slow thrombin.,Adams TE, Li W, Huntington JA J Thromb Haemost. 2009 Oct;7(10):1688-95. Epub 2009 Jul 28. PMID:19656282[21]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Wang W, Fu Q, Zhou R, Wu W, Ding Q, Hu Y, Wang X, Wang H, Wang Z. Prothrombin Shanghai: hypoprothrombinaemia caused by substitution of Gla29 by Gly. Haemophilia. 2004 Jan;10(1):94-7. PMID:14962227
- ↑ Board PG, Shaw DC. Determination of the amino acid substitution in human prothrombin type 3 (157 Glu leads to Lys) and the localization of a third thrombin cleavage site. Br J Haematol. 1983 Jun;54(2):245-54. PMID:6405779
- ↑ Rabiet MJ, Furie BC, Furie B. Molecular defect of prothrombin Barcelona. Substitution of cysteine for arginine at residue 273. J Biol Chem. 1986 Nov 15;261(32):15045-8. PMID:3771562
- ↑ Miyata T, Morita T, Inomoto T, Kawauchi S, Shirakami A, Iwanaga S. Prothrombin Tokushima, a replacement of arginine-418 by tryptophan that impairs the fibrinogen clotting activity of derived thrombin Tokushima. Biochemistry. 1987 Feb 24;26(4):1117-22. PMID:3567158
- ↑ Inomoto T, Shirakami A, Kawauchi S, Shigekiyo T, Saito S, Miyoshi K, Morita T, Iwanaga S. Prothrombin Tokushima: characterization of dysfunctional thrombin derived from a variant of human prothrombin. Blood. 1987 Feb;69(2):565-9. PMID:3801671
- ↑ Henriksen RA, Mann KG. Identification of the primary structural defect in the dysthrombin thrombin Quick I: substitution of cysteine for arginine-382. Biochemistry. 1988 Dec 27;27(26):9160-5. PMID:3242619
- ↑ Henriksen RA, Mann KG. Substitution of valine for glycine-558 in the congenital dysthrombin thrombin Quick II alters primary substrate specificity. Biochemistry. 1989 Mar 7;28(5):2078-82. PMID:2719946
- ↑ Miyata T, Aruga R, Umeyama H, Bezeaud A, Guillin MC, Iwanaga S. Prothrombin Salakta: substitution of glutamic acid-466 by alanine reduces the fibrinogen clotting activity and the esterase activity. Biochemistry. 1992 Aug 25;31(33):7457-62. PMID:1354985
- ↑ Morishita E, Saito M, Kumabashiri I, Asakura H, Matsuda T, Yamaguchi K. Prothrombin Himi: a compound heterozygote for two dysfunctional prothrombin molecules (Met-337-->Thr and Arg-388-->His). Blood. 1992 Nov 1;80(9):2275-80. PMID:1421398
- ↑ Iwahana H, Yoshimoto K, Shigekiyo T, Shirakami A, Saito S, Itakura M. Detection of a single base substitution of the gene for prothrombin Tokushima. The application of PCR-SSCP for the genetic and molecular analysis of dysprothrombinemia. Int J Hematol. 1992 Feb;55(1):93-100. PMID:1349838
- ↑ James HL, Kim DJ, Zheng DQ, Girolami A. Prothrombin Padua I: incomplete activation due to an amino acid substitution at a factor Xa cleavage site. Blood Coagul Fibrinolysis. 1994 Oct;5(5):841-4. PMID:7865694
- ↑ Degen SJ, McDowell SA, Sparks LM, Scharrer I. Prothrombin Frankfurt: a dysfunctional prothrombin characterized by substitution of Glu-466 by Ala. Thromb Haemost. 1995 Feb;73(2):203-9. PMID:7792730
- ↑ Casas JP, Hingorani AD, Bautista LE, Sharma P. Meta-analysis of genetic studies in ischemic stroke: thirty-two genes involving approximately 18,000 cases and 58,000 controls. Arch Neurol. 2004 Nov;61(11):1652-61. PMID:15534175 doi:61/11/1652
- ↑ Pihusch R, Buchholz T, Lohse P, Rubsamen H, Rogenhofer N, Hasbargen U, Hiller E, Thaler CJ. Thrombophilic gene mutations and recurrent spontaneous abortion: prothrombin mutation increases the risk in the first trimester. Am J Reprod Immunol. 2001 Aug;46(2):124-31. PMID:11506076
- ↑ Ohlin AK, Marlar RA. The first mutation identified in the thrombomodulin gene in a 45-year-old man presenting with thromboembolic disease. Blood. 1995 Jan 15;85(2):330-6. PMID:7811989
- ↑ Ohlin AK, Norlund L, Marlar RA. Thrombomodulin gene variations and thromboembolic disease. Thromb Haemost. 1997 Jul;78(1):396-400. PMID:9198186
- ↑ Faioni EM, Franchi F, Castaman G, Biguzzi E, Rodeghiero F. Mutations in the thrombomodulin gene are rare in patients with severe thrombophilia. Br J Haematol. 2002 Aug;118(2):595-9. PMID:12139752
- ↑ Delvaeye M, Noris M, De Vriese A, Esmon CT, Esmon NL, Ferrell G, Del-Favero J, Plaisance S, Claes B, Lambrechts D, Zoja C, Remuzzi G, Conway EM. Thrombomodulin mutations in atypical hemolytic-uremic syndrome. N Engl J Med. 2009 Jul 23;361(4):345-57. doi: 10.1056/NEJMoa0810739. PMID:19625716 doi:10.1056/NEJMoa0810739
- ↑ Maga TK, Nishimura CJ, Weaver AE, Frees KL, Smith RJ. Mutations in alternative pathway complement proteins in American patients with atypical hemolytic uremic syndrome. Hum Mutat. 2010 Jun;31(6):E1445-60. doi: 10.1002/humu.21256. PMID:20513133 doi:10.1002/humu.21256
- ↑ Glenn KC, Frost GH, Bergmann JS, Carney DH. Synthetic peptides bind to high-affinity thrombin receptors and modulate thrombin mitogenesis. Pept Res. 1988 Nov-Dec;1(2):65-73. PMID:2856554
- ↑ Adams TE, Li W, Huntington JA. Molecular basis of thrombomodulin activation of slow thrombin. J Thromb Haemost. 2009 Oct;7(10):1688-95. Epub 2009 Jul 28. PMID:19656282 doi:10.1111/j.1538-7836.2009.03563.x
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