Identification of the endothelial cell binding site for factor IX.

Cheung, Wing-Fai; Born, J van den; Kühn, Klaus; Kjellén, Lena; Hudson, Billy G.; Stafford, Darrel W.

doi:10.1073/pnas.93.20.11068

Cited by 88 publications

(105 citation statements)

References 29 publications

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“…21,22 While these results support the safe transduction of the target muscle by rAAV vectors leading to human factor IX expression, we cannot rule out from our studies that expressed factor IX may be bound locally, and thus sequestered from efficient delivery into the circulation. 23 It is interesting to note that the level of expression of factor IX observed in vitro increased gradually over 1 week after infection, achieving levels comparable to those previously reported in hemophilic dog fibroblasts following retroviral or adenovirus-polylysine-DNA factor IX gene delivery. 4,24 This increase with time is not unexpected, as both in vivo and in vitro experiments suggest AAV transduction increases gradually, reaching a plateau in the first weeks after infection 3,8 (also, Snyder and Muzyczka personal communication).…”

Section: Discussionsupporting

confidence: 79%

Direct intramuscular injection with recombinant AAV vectors results in sustained expression in a dog model of hemophilia

et al. 1998

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Section: Discussionsupporting

confidence: 79%

Direct intramuscular injection with recombinant AAV vectors results in sustained expression in a dog model of hemophilia

et al. 1998

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“…Amino acids 3-11 in the FIX Gla domain are critical for high affinity binding of the protein to aortic endothelial cells (57). It appears that this interaction is caused by binding of FIX to collagen IV and not phospholipid in the cell membrane (58). Using scanning force microscopy, Wolberg and colleagues (59) demonstrated that FIX binds specifically to collagen IV in the later molecule collagenous domain.…”

Section: Discussionmentioning

confidence: 99%

The Factor IX γ-Carboxyglutamic Acid (Gla) Domain Is Involved in Interactions between Factor IX and Factor XIa

Aktimur

Gabriel

Gailani

et al. 2003

Journal of Biological Chemistry

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During hemostasis, factor IX is activated to factor IXa␤ by factor VIIa and factor XIa. The glutamic acidrich ␥-carboxyglutamic acid (Gla) domain of factor IX is involved in phospholipid binding and is required for activation by factor VIIa. In contrast, activation by factor XIa is not phospholipid-dependent, raising questions about the importance of the Gla for this reaction. We examined binding of factors IX and IXa␤ to factor XIa by surface plasmon resonance. Plasma factors IX and IXa␤ bind to factor XIa with K d values of 120 ؎ 11 nM and 110 ؎ 8 nM, respectively. Recombinant factor IX bound to factor XIa with a K d of 107 nM, whereas factor IX with a factor VII Gla domain (rFIX/VII-Gla) and factor IX expressed in the presence of warfarin (rFIX-des␥) did not bind. An anti-factor IX Gla monoclonal antibody was a potent inhibitor of factor IX binding to factor XIa (K i 34 nM) and activation by factor XIa (K i 33 nM). In activated partial thromboplastin time clotting assays, the specific activities of plasma and recombinant factor IX were comparable (200 and 150 units/mg), whereas rFIX/VIIGla activity was low (<2 units/mg). In contrast, recombinant factor IXa␤ and activated rFIX/VIIa-Gla had similar activities (80 and 60% of plasma factor IXa␤), indicating that both proteases activate factor X and that the poor activity of zymogen rFIX/VII-Gla was caused by a specific defect in activation by factor XIa. The data demonstrate that factor XIa binds with comparable affinity to factors IX and IXa␤ and that the interactions are dependent on the factor IX Gla domain.

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“…In addition, unique protein-protein interactions sometimes involve the Gla domain. For example, factor IXa, factor VIIa, and protein C have been shown to bind specifically to collagen IV (20), tissue factor (21), and endothelial protein C receptor (22), respec-tively, through the Gla domain.…”

mentioning

confidence: 99%

Relocating the Active Site of Activated Protein C Eliminates the Need for Its Protein S Cofactor

Yegneswaran¹,

Smirnov²,

Safa³

et al. 1999

Journal of Biological Chemistry

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The effect of replacing the ␥-carboxyglutamic acid domain of activated protein C (APC) with that of prothrombin on the topography of the membrane-bound enzyme was examined using fluorescence resonance energy transfer. The average distance of closest approach (assuming 2 ‫؍‬ 2/3) between a fluorescein in the active site of the chimera and octadecylrhodamine at the membrane surface was 89 Å, compared with 94 Å for wildtype APC. The ␥-carboxyglutamic acid domain substitution therefore lowered and/or reoriented the active site, repositioning it close to the 84 Å observed for the APC⅐protein S complex. Protein S enhances wild-type APC cleavage of factor Va at Arg 306 , but the inactivation rate of factor Va Leiden by the chimera alone is essentially equal to that by wild-type APC plus protein S. These data suggest that the activities of the chimera and of the APC⅐protein S complex are equivalent because the active site of the chimeric protein is already positioned near the optimal location above the membrane surface to cleave Arg 306 . Thus, one mechanism by which protein S regulates APC activity is by relocating its active site to the proper position above the membrane surface to optimize factor Va cleavage.

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Identification of the endothelial cell binding site for factor IX.

Cited by 88 publications

References 29 publications

Direct intramuscular injection with recombinant AAV vectors results in sustained expression in a dog model of hemophilia

Direct intramuscular injection with recombinant AAV vectors results in sustained expression in a dog model of hemophilia

The Factor IX γ-Carboxyglutamic Acid (Gla) Domain Is Involved in Interactions between Factor IX and Factor XIa

Relocating the Active Site of Activated Protein C Eliminates the Need for Its Protein S Cofactor

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