Biomedical subjects

N Ananyeva

Publications and source records attributed to N Ananyeva.

3 recordsLinked to original sources

PubMed2002

Molecular defects in coagulation Factor VIII and their impact on Factor VIII function.

Molecular defects in Factor VIII (FVIII), such as haemophilia A-related mutations or denaturative conformational changes, may affect the stability of FVIII as well as its interactions with physiological activators, von Willebrand Factor, phospholipid, or conformationally sensitive antibodies. We summarize the contemporary assays which allow identification of impaired functional interactions of FVIII that cause a reduction or loss of its cofactor activity and/or increased immunogenicity. These assays can potentially be used for detection of molecular defects in FVIII and elucidation of the function impaired by these defects.

Blood Coagulation↗

PubMed2001

Comparison of the properties of phospholipid surfaces formed on HPA and L1 biosensor chips for the binding of the coagulation factor VIII.

Binding of a coagulation factor VIII to phosphatidylserine-containing membranes is critical for exerting its cofactor activity. The use of surface plasmon resonance allows studying factor VIII interaction with immobilized phospholipids. In the present study we compared factor VIII-binding properties of phospholipid surfaces immobilized on L1 and HPA Biacore chips in the form of a flexible bilayer and rigid monolayer, respectively. We demonstrated that immobilized phospholipid surfaces with physiological contents of PS and PE formed on L1 but not on HPA chip closely mimic intact phospholipid vesicles in their factor VIII and thrombin-activated factor VIII (factor VIIIa) binding properties.

Biosensing Techniques↗

PubMed2001

Molecular modifications in factor VIII concentrates produced from different plasma pools.

We defined the main cause for the increased immunogenicity of the commercial factor VIII (fVIII) plasma-derived concentrates reported to induce formation of inhibitory antibodies in haemophilia A patients in Germany and Belgium. Formation of these antibodies directed against the C2 domain of fVIII was previously attributed to the use of solvent/detergent (S/D) treatment and pasteurisation for virus inactivation of fVIII concentrate. Since fVIII concentrates associated with increased immunogenicity were prepared from plasma pools characterised by elevated levels of coagulation markers, we examined whether the plasma source or S/D treatment and pasteurisation are responsible for structural changes within the C2 domain causing its abnormal immunogenicity. We found that samples of fVIII concentrate that originated from the abnormal plasma pool had a reduced ability to bind to phospholipid and conformationally sensitive anti-C2 domain antibodies, this effect being mostly pronounced in the samples that underwent both S/D treatment and pasteurisation. Thus, our study suggests that insufficient quality of the starting plasma pools is the major factor determining the structural alterations in the C2 domain of fVIII, whereas combination of S/D treatment and pasteurisation aggravates these changes.

Antithrombin III↗