Perhaps you should try finding buffer conditions and protein concentration that pushes the self-association equilibrium to one particular oligomeric state.
Sent from Jack's iPad
On Sep 12, 2013, at 9:53 AM, "Debasish Kumar Ghosh" <[log in to unmask]> wrote:
> Hi,
>
> I am working with a protein which can assume different oligomerization forms, starting from monomers to trimers and even penta-decamers. We conformed this by Native PAGE and HPLC studies. The protein's theoretical monomeric molecular weight is 14.6 KDa (pI - 5.9) and it has some 140 amino acids with high Glutamic acid (24), Lysine (10) and Arginine (13) content. I have tried to crystallize it but not getting any hit as far now.
> Previous study showed that this protein gets some stability by Calcium ion. With the calcium chloride conditions, I am getting spherical shaped structures, but not sure what are they; calcium chloride crystals or protein crystals. Can protein crystals be spherical in shape, specially when the protein behaves like an oligomer?
> Also please let me know what is the minimum protein concentration required to obtain crystal for such small protein (if there is any empirical rule/idea).
> Any suggestion will be highly appreciated.
>
> Thanks and regards,
> Debasish Kumar Ghosh
>
> CSIR- Junior Research Fellow (PhD Scholar)
> C/o: Dr. Akash Ranjan
> Computational and Functional Genomics Group
> Centre for DNA Fingerprinting and Diagnostics
> Hyderabad, INDIA
>
> Email(s): [log in to unmask], [log in to unmask]
> Telephone: 0091-9088787619 (M), 0091-40-24749396 (Lab)
> Lab URL: http://www.cdfd.org.in/labpages/computational_functional_genomics.html
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