| 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]
Publication Abstract from PubMed
Protein C is activated by thrombin with a value of k(cat)/K(m)=0.11 mM(-1)s(-1) that increases 1,700-fold in the presence of the cofactor thrombomodulin. The molecular origin of this effect triggering an important feedback loop in the coagulation cascade remains elusive. Acidic residues in the activation domain of protein C are thought to electrostatically clash with the active site of thrombin. However, functional and structural data reported here support an alternative scenario. The thrombin precursor prethrombin-2 has R15 at the site of activation in ionic interaction with E14e, D14l and E18, instead of being exposed to solvent for proteolytic attack. Residues E160, D167 and D172 around the site of activation at R169 of protein C occupy the same positions as E14e, D14l and E18 in prethrombin-2. Caging of R169 by E160, D167 and D172 is responsible for much of the poor activity of thrombin toward protein C. The E160A/D167A/D172A mutant is activated by thrombin 63-fold faster than wild-type in the absence of thrombomodulin and, over a slower time scale, spontaneously converts to activated protein C. These findings establish a new paradigm for cofactor-assisted reactions in the coagulation cascade.
Exposure of R169 controls protein C activation and autoactivation.,Pozzi N, Barranco-Medina S, Chen Z, Di Cera E Blood. 2012 Apr 24. PMID:22535660[16]
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
- ↑ 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
- ↑ Pozzi N, Barranco-Medina S, Chen Z, Di Cera E. Exposure of R169 controls protein C activation and autoactivation. Blood. 2012 Apr 24. PMID:22535660 doi:10.1182/blood-2012-03-415323
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