NaOAc versus MgOAc? - protein extraction (Aug/15/2007 )

Hi there!
Is it ok to replace Magnesium oxaloacetate with Sodium oxaloacetate in a protein extraction buffer? Here is the recipe:
Homogenization buffer:
10 mM Tris–HCl buffer (pH 8.0)
0.32 M sucrose
3 mM CaCl2
2 mM MgOAc
0.1 mM EDTA
0.5% Nonidet P-40 (NP-40)
1 mM DTT
0.5 mM PMSF
4.0 μg/ml each of leupeptin, aprotinin and pepstatin.
Does anyone know?
Thanks guys

from the looks of the components in your solution i would think that you want the mg (you could probably use mgcl2 if you don't have the oxaloacetate and then use the naoac to ensure the presence of the oac).