Abstract
| Originalsprog | Engelsk |
|---|---|
| Tidsskrift | Journal of Biological Chemistry |
| Vol/bind | 283 |
| Udgave nummer | 38 |
| Sider (fra-til) | 25863-70 |
| Antal sider | 7 |
| ISSN | 0021-9258 |
| DOI | |
| Status | Udgivet - 2008 |
Bibliografisk note
Keywords: Aspartic Acid; Calcium; Crystallography, X-Ray; Factor VIIa; Glutamic Acid; Humans; Hydrogen; Hydrogen Bonding; Models, Molecular; Mutation; Protein Binding; Protein Structure, Tertiary; Static Electricity; Thromboplastin; Time FactorsAdgang til dokumentet
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Mechanism of the Ca2+-induced enhancement of the intrinsic factor VIIa activity. / Bjelke, Jais R; Olsen, Ole H; Fodje, Michel; Svensson, L Anders; Bang, Susanne; Bolt, Gert; Kragelund, Birthe B; Persson, Egon.
I: Journal of Biological Chemistry, Bind 283, Nr. 38, 2008, s. 25863-70.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review
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TY - JOUR
T1 - Mechanism of the Ca2+-induced enhancement of the intrinsic factor VIIa activity
AU - Bjelke, Jais R
AU - Olsen, Ole H
AU - Fodje, Michel
AU - Svensson, L Anders
AU - Bang, Susanne
AU - Bolt, Gert
AU - Kragelund, Birthe B
AU - Persson, Egon
N1 - Keywords: Aspartic Acid; Calcium; Crystallography, X-Ray; Factor VIIa; Glutamic Acid; Humans; Hydrogen; Hydrogen Bonding; Models, Molecular; Mutation; Protein Binding; Protein Structure, Tertiary; Static Electricity; Thromboplastin; Time Factors
PY - 2008
Y1 - 2008
N2 - The intrinsic activity of coagulation factor VIIa (FVIIa) is dependent on Ca(2+) binding to a loop (residues 210-220) in the protease domain. Structural analysis revealed that Ca(2+) may enhance the activity by attenuating electrostatic repulsion of Glu(296) and/or by facilitating interactions between the loop and Lys(161) in the N-terminal tail. In support of the first mechanism, the mutations E296V and D212N resulted in similar, about 2-fold, enhancements of the amidolytic activity. Moreover, mutation of the Lys(161)-interactive residue Asp(217) or Asp(219) to Ala reduced the amidolytic activity by 40-50%, whereas the K161A mutation resulted in 80% reduction. Hence one of these Asp residues in the Ca(2+)-binding loop appears to suffice for some residual interaction with Lys(161), whereas the more severe effect upon replacement of Lys(161) is due to abrogation of the interaction with the N-terminal tail. However, Ca(2+) attenuation of the repulsion between Asp(212) and Glu(296) keeps the activity above that of apoFVIIa. Altogether, our data suggest that repulsion involving Asp(212) in the Ca(2+)-binding loop suppresses FVIIa activity and that optimal activity requires a favorable interaction between the Ca(2+)-binding loop and the N-terminal tail. Crystal structures of tissue factor-bound FVIIa(D212N) and FVIIa(V158D/E296V/M298Q) revealed altered hydrogen bond networks, resembling those in factor Xa and thrombin, after introduction of the D212N and E296V mutations plausibly responsible for tethering the N-terminal tail to the activation domain. The charge repulsion between the Ca(2+)-binding loop and the activation domain appeared to be either relieved by charge removal and new hydrogen bonds (D212N) or abolished (E296V). We propose that Ca(2+) stimulates the intrinsic FVIIa activity by a combination of charge neutralization and loop stabilization.
AB - The intrinsic activity of coagulation factor VIIa (FVIIa) is dependent on Ca(2+) binding to a loop (residues 210-220) in the protease domain. Structural analysis revealed that Ca(2+) may enhance the activity by attenuating electrostatic repulsion of Glu(296) and/or by facilitating interactions between the loop and Lys(161) in the N-terminal tail. In support of the first mechanism, the mutations E296V and D212N resulted in similar, about 2-fold, enhancements of the amidolytic activity. Moreover, mutation of the Lys(161)-interactive residue Asp(217) or Asp(219) to Ala reduced the amidolytic activity by 40-50%, whereas the K161A mutation resulted in 80% reduction. Hence one of these Asp residues in the Ca(2+)-binding loop appears to suffice for some residual interaction with Lys(161), whereas the more severe effect upon replacement of Lys(161) is due to abrogation of the interaction with the N-terminal tail. However, Ca(2+) attenuation of the repulsion between Asp(212) and Glu(296) keeps the activity above that of apoFVIIa. Altogether, our data suggest that repulsion involving Asp(212) in the Ca(2+)-binding loop suppresses FVIIa activity and that optimal activity requires a favorable interaction between the Ca(2+)-binding loop and the N-terminal tail. Crystal structures of tissue factor-bound FVIIa(D212N) and FVIIa(V158D/E296V/M298Q) revealed altered hydrogen bond networks, resembling those in factor Xa and thrombin, after introduction of the D212N and E296V mutations plausibly responsible for tethering the N-terminal tail to the activation domain. The charge repulsion between the Ca(2+)-binding loop and the activation domain appeared to be either relieved by charge removal and new hydrogen bonds (D212N) or abolished (E296V). We propose that Ca(2+) stimulates the intrinsic FVIIa activity by a combination of charge neutralization and loop stabilization.
U2 - 10.1074/jbc.M800841200
DO - 10.1074/jbc.M800841200
M3 - Journal article
C2 - 18640965
VL - 283
SP - 25863
EP - 25870
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 38
ER -