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[ccp4bb]: RE: Crystal packing
Title:
Thank you all for your thoughtful suggestion. I think I should have stated
the crystal conditions and the experiment we have already done more clearly.
The protein is shown to be a monomer in solution by rate zonal centrifugation,
gel filtration, cross-linking, sedimentation equilibrium and low angle X-ray
scattering. Dynamic light scattering measurements indicated a monodisperse
solution with an apparent molecular weight of 79 kDa, which is in reasonable
agreement with that for the monomer (63.9 kDa). The protein is rather long
and thin, 146 x 46 x 34 Å.
Native protein is in 20 mM Tris-HCL, pH 8.5, and 50 mM sodium chloride. The
crystal conditions for these three crystal forms are somewhat similiar.
Form I crystals were crystallized in 30% MPD, 0.1 M sodium acetate at pH
4.6, 20 mM CaCl2. Form II was in 50% MPD,
0.1 M sodium acetate at pH 5.0, 10 mM CaCl2.
Form III: 63% MPD, 0.19 M sodium acetate at pH 4.53, 10 mM CaCl2,
with 0.1-0.2% final concentration of glutaraldehyde.
I will summarize all the answers as soon as possible.
Lan