Two different Ca2+ ion binding sites in factor VIIa and in des(1–38) factor VIIa
- 20 July 1992
- journal article
- Published by Wiley in FEBS Letters
- Vol. 306 (2-3) , 265-268
- https://doi.org/10.1016/0014-5793(92)81014-d
Abstract
The Ca2+ ion binding of factor VIIa and the derivative lacking the γ-carboxyglutamic acid domain, des(1–38) factor VIIa, was investigated using intrinsic protein fluorescence and Tb3+ ion phosphorescence methods. Binding of Ca2+ ions giving rise to a decrease in the intrinsic protein fluorescence (approximately 50% at saturating conditions) is seen with both proteins. Each of the saturation curves is in accordance with the formation of a 1:1 complex of factor VIIa-Ca2+ (KD∼30 μM) and des(1–38) factor VIIa-Ca2+ (KD∼40 μM)). Yet another Ca2+ ion binding site reveals itself in each protein in Tb3+ ion phosphorescence experiments. Ca2+ ion competition studies have showed 1:1 complexes (KD′s∼2 mM). The results are interpreted in terms of two different Ca2+ ion binding sites, one in the EGF-1 domain and one in the Gly-209-Gin-221 loop of the serine proteinase partKeywords
This publication has 12 references indexed in Scilit:
- Antibody-probed conformational transitions in the protease domain of human factor IX upon calcium binding and zymogen activation: putative high-affinity Ca(2+)-binding site in the protease domain.Proceedings of the National Academy of Sciences, 1992
- The gamma-carboxyglutamic acid domain of human factor VIIa is essential for its interaction with cell surface tissue factor.Journal of Biological Chemistry, 1990
- Amino acid sequence and posttranslational modifications of human factor VIIa from plasma and transfected baby hamster kidney cellsBiochemistry, 1988
- Calcium binding to the epidermal growth factor homology region of bovine protein C.Journal of Biological Chemistry, 1988
- Structure of native porcine pancreatic elastase at 1.65 Å resolutionActa crystallographica Section B, Structural science, crystal engineering and materials, 1988
- Affinity purification of human tissue factor: interaction of factor VII and tissue factor in detergent micelles.Proceedings of the National Academy of Sciences, 1986
- Structural changes required for activation of protein C are induced by Ca2+ binding to a high affinity site that does not contain gamma-carboxyglutamic acid.Journal of Biological Chemistry, 1983
- Terbium(III) emission as a probe of calcium(II) binding sites in proteinsJournal of the American Chemical Society, 1976
- The single calcium‐binding site of crystalline bovine β‐trypsinFEBS Letters, 1975