171 research outputs found
Interaction of prothrombin with factor Va-phospholipid complexes
The effects of factor Va and the phospholipid-binding fragment of factor Va [factor Va light chain (LC), Mr 80000] on the binding of prothrombin, factor X, and factor Xa to phospholipid vesicles are reported. Equilibrium binding experiments were performed that utilized large-volume vesicles, which can be removed from the bulk solution by centrifugation. Factor Va decreased the dissociation constant of the prothrombin-phospholipid complex 50-fold, from 2.0 X 10(-7) M to 4.0 X 10(-9) M. For the factor X-phospholipid complex the decrease was 60-fold (1.8 X 10(-7) M to 3.0 X 10(-9) M) and for factor Xa, 160-fold (1.6 X 10(-7) M to 1.0 X 10(-9) M). The ratios of moles of protein bound to moles of total added factor Va at saturation of phospholipid-bound factor Va indicate an 1:1 stoichiometric complex of either factor Xa, factor X, or prothrombin and phospholipid-bound factor Va. In the presence of factor Va LC, the dissociation constants of factor Xa- and prothrombin-phospholipid complexes were increased, while the maximal protein-binding capacities of the vesicles were not affected by factor Va LC. The data suggest a competitive interaction between factor Xa and factor Va LC binding as well as between prothrombin and factor Va LC binding at the phospholipid surface. From this, it is concluded that the phospholipid-binding fragment of factor Va alone does not serve as the binding site for interactions of factor Xa and prothrombin with factor Va
Design of the physical exercise during Adjuvant Chemotherapy Effectiveness Study (PACES): a randomized controlled trial to evaluate effectiveness and cost-effectiveness of physical exercise in improving physical fitness and reducing fatigue
Design of the physical exercise during Adjuvant Chemotherapy Effectiveness Study (PACES): a randomized controlled trial to evaluate effectiveness and cost-effectiveness of physical exercise in improving physical fitness and reducing fatigue
Interaction of bovine blood clotting factor Va and its subunits with phosolipid vesicles
Thrombin-activated factor Va and factor Va subunit binding to large-volume vesicles was investigated by a technique based on the separation by centrifugation of phospholipid-bound protein from the bulk solution. This technique allows the direct measurement of free-protein concentration. It is concluded that the phospholipid binding site on factor Va is located on a basic factor Va subunit with Mr 80 000 (factor Va-LC). The effects of phospholipid vesicle composition, calcium concentration, pH, and ionic strength on the equilibrium constants of factor Va- and factor Va-LC-phospholipid interaction were studied. Factor Va and factor Va-LC binding to phospholipid requires the presence of negatively charged phospholipids. It is further demonstrated that the following occur: (a) Calcium ions compete with factor Va and factor Va-LC for phospholipid-binding sites. (b) The dissociation constant of protein-phospholipid interaction increases with the ionic strength, whereas the maximum protein-binding capacity of the phospholipid vesicle was not affected by ionic strength. (c) The dissociation constant for factor Va-phospholipid interaction depends on pH when the vesicle consists of phosphatidic acid. It is concluded that factor Va-phospholipid interaction is primarily electrostatic in nature, where positively charged groups on the protein directly interact with the phosphate group of net negatively charged phospholipids. The results suggest that factor Va, like factor Xa and prothrombin, has the characteristics of an extrinsic membrane protein
Functional properties of factor Va subunits after proteolytic alterations by activated protein C
Effect of low versus high intensity physical exercise during chemotherapy on physical fitness, fatigue and chemotherapy completion rates:Results of a randomized, controlled trial
PACES-studie: een gerandomiseerde klinische studie naar de effectiviteit van beweging tijdens adjuvante chemotherapie ter verbetering van fysieke fitheid en vermindering van vermoeidheid
DESC9115 Lab Report 1
The implementation of the Vibrato and Flanger effect by Oscar GonzalezArchitecture & Allied Art
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