Dear community folks,
I’m trying to crystallize a protein (100kD) toward figuring out the molecular function through analyzing its atomic structure, despite it’s suspected this protein is involved in membrane fusion.
I purified this protein in satisfactory quality (>95% purity on SDS gel). The CD spectra analysis shows this protein is rich in alpha-helical structures (around 65% composition). I also collected good quality SAXS data and the low resolution model shows a S-shape architecture. Recently, I tried staining this protein with Uranium for EM analysis which shows the protein adopts a elongated structure. However, the EM images show a heterogeneous (with varying degrees of bending) structure population, that is, it’s difficult to determine which population typically represents the structure of this protein.
I still want to determine the crystal structure of the mysterious protein.
I hereby seek your expert opinions on the following inquiries.
1) Do you think this kind of protein, with elongated structure and maybe flexible regions, is extremely hard to crystallize in a conventional way?
2) Could you please recommend any special commercial screening kits for this purpose? I have tried with Qiagen kits but there have been no hits.
3) Is lipidic cubic phase a worthy choice for crystallization in current status? My results on interaction between this protein and liposomes (different compositions) were negative.
Thanks a lot in advance for your inputs!
Sincerely
Wenhua
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