| 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
Anopheles mosquitoes are vectors of malaria, a potentially fatal blood disease affecting half a billion humans worldwide. These blood-feeding insects include in their antihemostatic arsenal a potent thrombin inhibitor, the flexible and cysteine-less anophelin. Here, we present a thorough structure-and-function analysis of thrombin inhibition by anophelin, including the 2.3-A crystal structure of the human thrombin.anophelin complex. Anophelin residues 32-61 are well-defined by electron density, completely occupying the long cleft between the active site and exosite I. However, in striking contrast to substrates, the D50-R53 anophelin tetrapeptide occupies the active site cleft of the enzyme, whereas the upstream residues A35-P45 shield the regulatory exosite I, defining a unique reverse-binding mode of an inhibitor to the target proteinase. The extensive interactions established, the disruption of thrombin's active site charge-relay system, and the insertion of residue R53 into the proteinase S(1) pocket in an orientation opposed to productive substrates explain anophelin's remarkable specificity and resistance to proteolysis by thrombin. Complementary biophysical and functional characterization of point mutants and truncated versions of anophelin unambiguously establish the molecular mechanism of action of this family of serine proteinase inhibitors (I77). These findings have implications for the design of novel antithrombotics.
Unique thrombin inhibition mechanism by anophelin, an anticoagulant from the malaria vector.,Figueiredo AC, de Sanctis D, Gutierrez-Gallego R, Cereija TB, Macedo-Ribeiro S, Fuentes-Prior P, Pereira PJ Proc Natl Acad Sci U S A. 2012 Dec 26;109(52):E3649-58. doi:, 10.1073/pnas.1211614109. Epub 2012 Dec 5. PMID:23223529[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
- ↑ Figueiredo AC, de Sanctis D, Gutierrez-Gallego R, Cereija TB, Macedo-Ribeiro S, Fuentes-Prior P, Pereira PJ. Unique thrombin inhibition mechanism by anophelin, an anticoagulant from the malaria vector. Proc Natl Acad Sci U S A. 2012 Dec 26;109(52):E3649-58. doi:, 10.1073/pnas.1211614109. Epub 2012 Dec 5. PMID:23223529 doi:http://dx.doi.org/10.1073/pnas.1211614109
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