Note. The rotational correlation time (τrotc) of BGP can be estimated to approximately 2 ns at 20°C from the Debye-Stokes-Einstein equation . We are thus able to determine an upper limit of ωτc in our experiments: ωτ2 < 0.22 (ω= 1.078 · 108 s−1 and τc <2 · 10−9 s).
Calcium binding to bone γ-carboxyglutamic acid protein from calf studied by 43Ca NMR
Article first published online: 3 MAR 2005
European Journal of Biochemistry
Volume 158, Issue 2, pages 373–376, July 1986
How to Cite
SVÄRD, M., DRAKENBERG, T., ANDERSSON, T. and FERNLUND, P. (1986), Calcium binding to bone γ-carboxyglutamic acid protein from calf studied by 43Ca NMR. European Journal of Biochemistry, 158: 373–376. doi: 10.1111/j.1432-1033.1986.tb09762.x
- Issue published online: 3 MAR 2005
- Article first published online: 3 MAR 2005
- (Received March 13, 1986) – EJB 86 0257
Calcium binding to bone γ-carboxyglutamic acid protein (BGB) from calf has been studied using 43Ca NMR. The temperature dependence of the 43Ca NMR signal has been used to calculate the calcium ion exchange rate, koff. The dependence of the 43Ca NMR band shape on the [Ca2+]/[BGP] ratio fits well to a chemical equilibrium model having a single Ca2+ -binding site with an association constant in the range of 5 × 103–1 × 105 M−1. The pH dependence of the 43Ca NMR line-width shows a single apparent pKa value of 5.1.