Engineering of a membrane-triggered activity switch in coagulation factor VIIa.
Proc Natl Acad Sci U S A
; 114(47): 12454-12459, 2017 11 21.
Article
em En
| MEDLINE
| ID: mdl-29109275
ABSTRACT
Recombinant factor VIIa (FVIIa) variants with increased activity offer the promise to improve the treatment of bleeding episodes in patients with inhibitor-complicated hemophilia. Here, an approach was adopted to enhance the activity of FVIIa by selectively optimizing substrate turnover at the membrane surface. Under physiological conditions, endogenous FVIIa engages its cell-localized cofactor tissue factor (TF), which stimulates activity through membrane-dependent substrate recognition and allosteric effects. To exploit these properties of TF, a covalent complex between FVIIa and the soluble ectodomain of TF (sTF) was engineered by introduction of a nonperturbing cystine bridge (FVIIa Q64C-sTF G109C) in the interface. Upon coexpression, FVIIa Q64C and sTF G109C spontaneously assembled into a covalent complex with functional properties similar to the noncovalent wild-type complex. Additional introduction of a FVIIa-M306D mutation to uncouple the sTF-mediated allosteric stimulation of FVIIa provided a final complex with FVIIa-like activity in solution, while exhibiting a two to three orders-of-magnitude increase in activity relative to FVIIa upon exposure to a procoagulant membrane. In a mouse model of hemophilia A, the complex normalized hemostasis upon vascular injury at a dose of 0.3 nmol/kg compared with 300 nmol/kg for FVIIa.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Terapia Biológica
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Tromboplastina
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Engenharia de Proteínas
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Fator VIIa
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Hemofilia A
Tipo de estudo:
Prognostic_studies
Limite:
Animals
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Female
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Humans
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Male
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Dinamarca