|
| |
| | CRISP - Computer Retrieval of Information on Scientific Projects, Abstract Display |
 | | A focal point is the study of proteolysis at Arg336 in the A1 subunit, a predominant site cleaved by both APC and factor Xa, and the influence of attack at this site on cleavage at more secondary sites. | | | Studies will focus on the A2 subunit based upon our observations that this subunit contains an extended factor IXa-interactive surface and that isolated A2 enhances the kcat for factor IXa-catalyzed activation of factor X. A primary effort will focus on experimentally assessing and refining our model for the A2-factor IXa interface. | | | The activated form of factor VIII, factor VIIIa, functions as a cofactor for the factor IXa-dependent activation of factor X, increasing the kcat for this reaction by several orders of magnitude. |
|
http://crisp.cit.nih.gov/crisp/CRISP_LIB.getdoc?textkey=6754692&p_grant_num=1R01HL076213-01&p_query=&ticket=8377139&p_audit_session_id=37895219&p_keywords=
(398 words)
|
|
| |
| | Activated Partial Thromboplastin Time |
| | Therefore, in these situations, an alternative assay, such as the Heparin Antifactor Xa Assay, should be used rather than the PTT to monitor heparin. | | | Factor deficiencies that prolong PTT: The PTT is more sensitive to deficiencies of the intrinsic pathway (factors VIII, IX, XI, XII, prekallikrein, HMWK) than it is to deficiencies of the common pathway (fibrinogen, and factors II, V, and X). | | | The PTT is more sensitive to intrinsic pathway factor deficiencies than to common pathway factor deficiencies. |
|
http://www.mgh.harvard.edu/labmed/lab/coag/handbook/co003400.htm
(398 words)
|
|
| |
| | New Page 1 |
| | · Factor Xa forms the crossroads of the two clotting systems by participating in both the extrinsic and the intrinsic pathways. | | | Platelet activation I ntrinsic Pathway Extrinsic Pathway Tissue factor Pathway | | | Although factor XII, prekallikrein (Fletcher factor), and high molecular weight kininogen (Fitzgerald factor) are all essential for normal clotting in the test tube, their biological purpose for clotting is uncertain. |
|
http://www.reddymed.com/hdbc/pathwayintrinsic.htm
(5742 words)
|
|
| |
| | Philip J. Fay Faculty Page |
| | Factor VIII serves as a protein cofactor for the serine protease, factor IXa in the surface-dependent conversion of factor X to factor Xa during the blood coagulation cascade reactions. | | | Jenkins PV, Dill JL, Zhou Q, Fay PJ (2004) Contribution of factor VIIIa A2 and A3-C1-C2 subunits to the affinity for factor IXa in factor Xase. | | | Nogami K, Freas J, Manithody C, Wakabayashi H, Rezaie AR, Fay PJ (2004) Mechanisms of interactions of factor X and factor Xa with the acidic region in the factor VIII A1 domain. |
|
http://dbb.urmc.rochester.edu/bcbp/members/faculty/fay_Philip.html
(571 words)
|
|
| |
| | OUTPUT from blastx for SL1-0303 |
| | Factor Xa Specific Inhibitor In Complex With Bovine Trypsin pdb1MTV | | | Factor Xa Specific Inhibitor In Complex With Bovine Trypsin pdb1MTW | | | Factor Xa Specific Inhibitor In Complex With Bovine Trypsin pdb1MTU |
|
http://cbr-rbc.nrc-cnrc.gc.ca/reith/salmon/liver/SL1-0303.html
(571 words)
|
|
| |
| | annual report 97 |
| | Factor Xa protease sites were inserted into thirteen individual positions in GAP1; one at the N-terminus, 11 in the middle of each hydrophilic loop and one at the C-terminus. | | | Comparative localization of fibroblast gorwth factor receptor-1, -2, and -3 mRNAs in the rat brain: In situ hybridization analysis. | | | Finally, growth factors regulating the formation of new blood vessels (angiogenesis) is a new and increasingly important area of interest at the Branch. |
|
http://www.licr.ki.se/annrep97.html
(571 words)
|
|
| |
| | General Clotting Information |
| | Factor V and factor VIII (shown in light green) accelerate the conversion of factor X to factor Xa by factor IXa (this is done by factor VIII) and accelerate the conversion of prothrombin to thrombin as done by factor Xa. | | | Factor Xa is then able to activate prothrombin (also referred to as factor II) to form thrombin (factor IIa). | | | Tissue factor and factor VIIa (the 'a' denotes the active form of the factor) activate factor X, forming factor Xa. |
|
http://www-admin.med.uiuc.edu/hematology/PtClotInfo.htm
(672 words)
|
|
| |
| | THE MERCK MANUAL, Sec. 11, Ch. 131, Hemostasis And Coagulation Disorders |
| | The resultant tissue factor pathway inhibitor/factor Xa (lipoprotein-associated coagulation inhibitor/Xa) complexes bind to factor VIIa on tissue factor, giving rise to factor VIIa/tissue factor/tissue factor pathway inhibitor/factor Xa complexes that lack catalytic activity. | | | Factor X activation requires both routes for normal hemostasis, presumably because the catalytic activity of factor VIIa/tissue factor is inhibited as coagulation proceeds by a factor Xa-dependent mechanism. | | | Hemostasis, the arrest of bleeding from an injured blood vessel, requires the combined activity of vascular, platelet, and plasma factors counterbalanced by regulatory mechanisms to limit the accumulation of platelets and fibrin in the area of injury. |
|
http://www.merck.com/pubs/mmanual/section11/chapter131/131b.htm
(3057 words)
|
|
| |
| | CHEST: The heparin anti-Xa therapeutic range: are we there yet? - communications to the editor - Letter to the Editor |
| | The authors concluded that the therapeutic range for heparin anti-factor Xa analysis may need to be specific for the instrument and method. | | | These investigators also assessed the equivalency of the heparin anti-factor Xa levels using the Stachrom technique to protamine sulfate titration. | | | Heparin levels by protamine sulfate titration of 0.2 to 0.4 U/mL were equivalent to chromogenic heparin anti-factor Xa levels of 0.35 to 0.67 U/mL using the Stachrom technique. |
|
http://www.findarticles.com/p/articles/mi_m0984/is_1_121/ai_83028402
(6972 words)
|
|
| |
| | Factor V: a combination of Dr Jekyll and Mr Hyde -- Mann and Kalafatis 101 (1): 20 -- Blood |
| | Prothrombin activation by factor Xa in the absence of factor Va and in the absence and presence of membranes. | | | Factor V is the inactive precursor of factor Va that contributes factor Xa receptor and catalytic effector functions to prothrombinase. | | | A fundamental contribution of factor Va to prothrombinase function is the retention of factor Xa on the membrane surface. |
|
http://www.bloodjournal.org/cgi/content/full/101/1/20
(6894 words)
|
|
| |
| | THE MERCK MANUAL, Sec. 11, Ch. 131, Hemostasis And Coagulation Disorders |
| | Coagulation occurs in steps: (1) Sequences of reactions in at least two pathways (the intrinsic and extrinsic pathways) activate serine protease proenzymes and form a prothrombin activator, which is a complex (of an enzyme; factor Xa; and two cofactors, factor Va and procoagulant phospholipid) on the surface of activated platelets or tissue cells. | | | Factor X activation requires both routes for normal hemostasis, presumably because the catalytic activity of factor VIIa/tissue factor is inhibited as coagulation proceeds by a factor Xa-dependent mechanism. | | | (Because commercial reagents and instrumentation vary widely, each laboratory should determine its own normal range; 28 to 34 sec is typical.) The PTT is sensitive to deficiencies of 30 to 40% of all clotting factors except factors VII and XIII. |
|
http://www.merck.com/mrkshared/mmanual/section11/chapter131/131b.jsp
(3057 words)
|
|
| |
| | Reference Detail |
| | The procoagulant activity of factor Xa in a one-stage plasma coagulation assay is reduced when factor Xa is first incubated with PZ. | | | The inhibitory process appears to involve the formation of a factor Xa-PZ-ZPI complex at the phospholipid surface. | | | In serum the initial rate of inhibition of factor Xa with calcium ions and cephalin also is enhanced in the presence PZ. |
|
http://biopd.bjmu.edu.cn/RefDetailPage.asp?ID=9689066
(3057 words)
|
|
| |
| | Factor V: a combination of Dr Jekyll and Mr Hyde -- Mann and Kalafatis 101 (1): 20 -- Blood |
| | Prothrombin activation by factor Xa in the absence of factor Va and in the absence and presence of membranes. | | | A fundamental contribution of factor Va to prothrombinase function is the retention of factor Xa on the membrane surface. | | | The role of the membrane in the inactivation of factor Va by plasmin: amino acid region 307-348 of factor V plays a critical role for factor Va cofactor function. |
|
http://www.bloodjournal.org/cgi/content/full/101/1/20
(6894 words)
|
|
| |
| | Philip J. Fay Faculty Page |
| | Factor VIII serves as a protein cofactor for the serine protease, factor IXa in the surface-dependent conversion of factor X to factor Xa during the blood coagulation cascade reactions. | | | Jenkins PV, Dill JL, Zhou Q, Fay PJ (2004) Contribution of factor VIIIa A2 and A3-C1-C2 subunits to the affinity for factor IXa in factor Xase. | | | A second major focus of our lab is to elucidate the molecular basis for the cofactor effect following reconstitution of the intrinsic factor Xase complex (factor IXa, factor VIIIa (or isolated subunits) plus phospholipid vesicles) using purified components. |
|
http://dbb.urmc.rochester.edu/bcbp/members/faculty/fay_Philip.html
(545 words)
|
|
| |
| | Novagen: 69037: Factor Xa Cleavage Capture Kit |
| | After cleavage of the target protein, Factor Xa is removed with greater than 99% efficiency from the reaction by affinity capture on Xarrest™ Agarose. | | | The Factor Xa Cleavage Capture Kit is designed for highly specific cleavage of fusion proteins followed by convenient affinity-based capture and removal of Factor Xa. | | | The 49 kDa Xa Cleavage Control Protein is cleaved into two proteolytic fragments of 32 kDa and 17 kDa, which are easily visualized by standard SDS-PAGE followed by Coomassie blue staining. |
|
http://www.emdbiosciences.com/product/69037
(353 words)
|
|
| |
| | eMedicine - Factor VII : Article Excerpt by: Jeyanthi Ramanarayanan, MD |
| | Factor VIIa bound to tissue factor in the presence of calcium and phospholipids facilitates the conversion of factor IX to factors IXa and X to factor Xa. | | | In 1951, Alexander and colleagues identified factor VII as the key initiator of coagulation when they reported the first case of factor VII deficiency in a child and called it serum prothrombin conversion accelerator deficiency. | | | This facilitates conversion of factor VII to factor VIIa. |
|
http://www.emedicine.com/med/byname/factor-vii.htm
(671 words)
|
|
| |
| | F10 - Coagulation factor X precursor |
| | Plasma levels of tissue factor pathway inhibitor (TFPI)-activated factor Xa (FXa) complex were measured in patients with disseminated intravascular coagulation (DIC), pre-DIC, and DIC. | | | Human blood coagulation factor X has two N-linked oligosaccharides at Asn39 and Asn49 residues and two O-linked oligosaccharides at Thr17 and Thr29 residues in the region of the factor X activation peptide (XAP) which is cleaved off during its activation by factor IXa. | | | [ Chromogenic substrates for determining coagulation factor X and their use in clinical practice (review of the literature)]. |
|
http://www.pdg.cnb.uam.es/UniPub/iHOP/gi/88111.html
(671 words)
|
|
| |
| | Hepsin, a Putative Membrane-associated Serine Protease, Activates Human Factor VII and Initiates a Pathway of Blood Coagulation on the Cell Surface Leading to Thrombin Formation -- Kazama et al. 270 (1): 66 -- Journal of Biological Chemistry |
| | In some of these tumor types, such as malignant melanoma, functional factor Xa has been observed without detectable tissue factor and factor VII antigen(44), suggesting that these cells synthesize cancer procoagulant, a cysteinyl protease(45), that activates factor X directly. | | | While tissue factor synthesis and expression by several tumor types has been implicated as the major contributor to fibrin deposition on these tumor cells, there are specific instances of tumor tissues that support fibrin formation yet lack immunoreactive tissue factor(7). | | | In addition, several tumor cells generate thrombin and fibrin without detectable cell-surface tissue factor, and precisely how this happens is unknown although cancer procoagulant A synthesis by these cells has been implicated in this mechanism(7). |
|
http://www.jbc.org/cgi/content/full/270/1/66
(671 words)
|
|
| |
| | ed_ich_protocol.htm |
| | Low Molecular Weight Heparin--Protamine sulfate reverses only about 60% of the anti-factor Xa activity of low-molecular-weight heparin, has negligible effects on danaparoid (a mixture of anticoagulant glycosaminoglycans used to treat heparin-induced thrombocytopenia) and fondaparinux (a synthetic antithrombin-binding pentasaccharide with exclusive anti-factor Xa activity). | | | Enoxaparin: 1 mg protamine for each mg of enoxaparin; if PTT prolonged 2-4 hours after first dose, consider additional dose of 0.5 mg for each mg of enoxaparin. | | | Dalteparin or tinzaparin: 1 mg protamine for each 100 anti-Xa IU of dalteparin or tinzaparin; if PTT prolonged 2-4 hours after first dose, consider additional dose of 0.5 mg for each 100 anti-Xa IU of dalteparin or tinzaparin. |
|
http://neuro-oas.mgh.harvard.edu/stopstroke/ed_ich_protocol.htm
(361 words)
|
|
|
