As far as I know, there is no specific rule with the concentration for the crystallization. There are some pre-crystallization tests available, mainly from the hampton research which may help you to determine the appropriate concentration for the crystallization. Coming to the spherical structures, it may be quasicrystals. Just try by increasing the concentration when you screen again.
On Thu, Sep 12, 2013 at 4:42 PM, Debasish Kumar Ghosh <dkgh...@cdfd.org.in>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): dkgh...@cdfd.org.in, dgho...@gmail.com > Telephone: 0091-9088787619 (M), 0091-40-24749396 (Lab) > Lab URL: > http://www.cdfd.org.in/labpages/computational_functional_genomics.html > -- Vikram Babu Kasaragod Graduate Student Hermann Schindelin Group Rudolf Virchow Center University of Wuerzburg Josef-Schneider-Straße 2, Haus D15 D - 97080 Würzburg. email: vikram.kasara...@uni-wuerzburg.de website: www.rudolf-virchow-zentrum.de Phone : +49 931 31-89938 Fax: +49 931 31-83255
