Factor X

Para outras páxinas con títulos homónimos véxase: Factor X (programa de televisión).

Non confundir con [[:factor X (un factor de crecemento para o cultivo da bacteria Haemophilus influenzae correspondente á protroporfirina IX ou hemina)]].

O factor X (factor dez) de coagulación, tamén chamado factor de Stuart–Prower, é un encima (EC 3.4.21.6) da fervenza de coagulación do sangue. É unha serina endopeptidase (protease do grupo S1, clan PA). O factor X é sintetizado no fígado e require vitamina K para a súa síntese.

O factor X é activado por hidrólise dando lugar ao factor Xa por acción do factor IX (co seu cofactor o factor VIII nun complexo chamado Xase intrínseca) ou polo factor VII (co seu cofactor factor tisular, formando un complexo chamado Xase extrínseca). É, por tanto, o primeiro membro da vía común final ou vía da trombina da coagulación.

Actúa clivando a protrombina en dous sitios (un enlace Arg-Thr e outro Arg-Ile), orixinando a trombina activa. Este proceso está optimizado cando o factor Xa está en acomplexado co cofactor V activado no complexo da protrombinase.

O factor Xa é inactivado polo inhibidor da protease dependente da proteína Z (ZPI), un inhibidor da serina protease (serpina). A afinidade desta proteína polo factor Xa multiplícase por mil en presenza da proteína Z, mentresque non cómpre proteína Z par a inactivación do factor XI. Os defectos na proteína Z causan un incremento da actividade do factor Xa e unha propensión á trombose.

A vida media do factor X é de entre 40 e 45 horas.

Historia

Científicos estadounidenses e británicos describiron a deficiencia de factor X independentemente en 1953 e 1956, respectivamente. Igual que algúns outros factores de cosgulación, o factor foi inicialmente nomeado polo nome dos pacientes nos que se atopou a deficiencia, chamados Rufus Stuart (1921) e Audrey Prower (1934), polo que se denominou factor Stuart-Prower.

Interaccións

O factor X presenta interaccións co inhibidor da vía do factor tisular.

Véxase tamén

Ligazóns externas

• A base de datos en liña MEROPS para peptidases e os seus inhibidores: S01.216
• Modelo:EMedicine
• Deficiencia de factor X

Bibliografía

• Cooper DN, Millar DS, Wacey A, Pemberton S, Tuddenham EG (July 1997). "Inherited factor X deficiency: molecular genetics and pathophysiology". Thrombosis and Haemostasis 78 (1): 161–72. PMID 9198147. 
• Hassan HJ, Leonardi A, Chelucci C, Mattia G, Macioce G, Guerriero R, Russo G, Mannucci PM, Peschle C (September 1990). "Blood coagulation factors in human embryonic-fetal development: preferential expression of the FVII/tissue factor pathway". Blood 76 (6): 1158–64. PMID 1698100. 
• Messier TL, Pittman DD, Long GL, Kaufman RJ, Church WR (March 1991). "Cloning and expression in COS-1 cells of a full-length cDNA encoding human coagulation factor X". Gene 99 (2): 291–4. PMID 1902434. doi:10.1016/0378-1119(91)90141-W. 
• Krishnaswamy S (March 1990). "Prothrombinase complex assembly. Contributions of protein-protein and protein-membrane interactions toward complex formation". The Journal of Biological Chemistry 265 (7): 3708–18. PMID 2303476. 
• España F, Berrettini M, Griffin JH (August 1989). "Purification and characterization of plasma protein C inhibitor". Thrombosis Research 55 (3): 369–84. PMID 2551064. doi:10.1016/0049-3848(89)90069-8. 
• Fung MR, Hay CW, MacGillivray RT (June 1985). "Characterization of an almost full-length cDNA coding for human blood coagulation factor X". Proceedings of the National Academy of Sciences of the United States of America 82 (11): 3591–5. PMC 397831. PMID 2582420. doi:10.1073/pnas.82.11.3591. 
• Jagadeeswaran P, Reddy SV, Rao KJ, Hamsabhushanam K, Lyman G (December 1989). "Cloning and characterization of the 5' end (exon 1) of the gene encoding human factor X". Gene 84 (2): 517–9. PMID 2612918. doi:10.1016/0378-1119(89)90529-5. 
• Reddy SV, Zhou ZQ, Rao KJ, Scott JP, Watzke H, High KA, Jagadeeswaran P (October 1989). "Molecular characterization of human factor XSan Antonio". Blood 74 (5): 1486–90. PMID 2790181. 
• Kaul RK, Hildebrand B, Roberts S, Jagadeeswaran P (1986). "Isolation and characterization of human blood-coagulation factor X cDNA". Gene 41 (2-3): 311–4. PMID 3011603. doi:10.1016/0378-1119(86)90112-5. 
• Broze GJ, Warren LA, Novotny WF, Higuchi DA, Girard JJ, Miletich JP (February 1988). "The lipoprotein-associated coagulation inhibitor that inhibits the factor VII-tissue factor complex also inhibits factor Xa: insight into its possible mechanism of action". Blood 71 (2): 335–43. PMID 3422166. 
• Gilgenkrantz S, Briquel ME, André E, Alexandre P, Jalbert P, Le Marec B, Pouzol P, Pommereuil M (1986). "Structural genes of coagulation factors VII and X located on 13q34". Annales De Genetique 29 (1): 32–5. PMID 3487272. 
• Leytus SP, Foster DC, Kurachi K, Davie EW (September 1986). "Gene for human factor X: a blood coagulation factor whose gene organization is essentially identical with that of factor IX and protein C". Biochemistry 25 (18): 5098–102. PMID 3768336. doi:10.1021/bi00366a018. 
• Leytus SP, Chung DW, Kisiel W, Kurachi K, Davie EW (June 1984). "Characterization of a cDNA coding for human factor X". Proceedings of the National Academy of Sciences of the United States of America 81 (12): 3699–702. PMC 345286. PMID 6587384. doi:10.1073/pnas.81.12.3699. 
• McMullen BA, Fujikawa K, Kisiel W, Sasagawa T, Howald WN, Kwa EY, Weinstein B (June 1983). "Complete amino acid sequence of the light chain of human blood coagulation factor X: evidence for identification of residue 63 as beta-hydroxyaspartic acid". Biochemistry 22 (12): 2875–84. PMID 6871167. doi:10.1021/bi00281a016. 
• Marchetti G, Castaman G, Pinotti M, Lunghi B, Di Iasio MG, Ruggieri M, Rodeghiero F, Bernardi F (August 1995). "Molecular bases of CRM+ factor X deficiency: a frequent mutation (Ser334Pro) in the catalytic domain and a substitution (Glu102Lys) in the second EGF-like domain". British Journal of Haematology 90 (4): 910–5. PMID 7669671. doi:10.1111/j.1365-2141.1995.tb05214.x. 
• Morgenstern KA, Sprecher C, Holth L, Foster D, Grant FJ, Ching A, Kisiel W (March 1994). "Complementary DNA cloning and kinetic characterization of a novel intracellular serine proteinase inhibitor: mechanism of action with trypsin and factor Xa as model proteinases". Biochemistry 33 (11): 3432–41. PMID 8136380. doi:10.1021/bi00177a037. 
• Heeb MJ, Rosing J, Bakker HM, Fernandez JA, Tans G, Griffin JH (March 1994). "Protein S binds to and inhibits factor Xa". Proceedings of the National Academy of Sciences of the United States of America 91 (7): 2728–32. PMC 43443. PMID 8146182. doi:10.1073/pnas.91.7.2728. 
• Inoue K, Morita T (November 1993). "Identification of O-linked oligosaccharide chains in the activation peptides of blood coagulation factor X. The role of the carbohydrate moieties in the activation of factor X". European Journal of Biochemistry 218 (1): 153–63. PMID 8243461. doi:10.1111/j.1432-1033.1993.tb18361.x. 
• Padmanabhan K, Padmanabhan KP, Tulinsky A, Park CH, Bode W, Huber R, Blankenship DT, Cardin AD, Kisiel W (August 1993). "Structure of human des(1-45) factor Xa at 2.2 A resolution". Journal of Molecular Biology 232 (3): 947–66. PMID 8355279. doi:10.1006/jmbi.1993.1441. 
• Sinha U, Wolf DL (February 1993). "Carbohydrate residues modulate the activation of coagulation factor X". The Journal of Biological Chemistry 268 (5): 3048–51. PMID 8428982.