My interpretation of hollow crystals is that the crystals are growing too fast. I've had success with similar looking crystals by slowing crystal growth. You can try lower temperature, protein concentration, or precipitant. In my case, I found success by trying different concentrations of NaCl in the reservoir (see Janet Newman, Acta Cryst D, 61:490).
ho From: rui <ruis...@gmail.com> Subject: how to improve resolution --0016e6d7ee96984676047ed308d5 Content-Type: text/plain; charset=ISO-8859-1 Hi, All, We are trying to crystallize a protein and found some initial hit in the following conditions, pH 4.8, 0.2 M AS or some other salts ( NaCl,LiCl, MgCl2 ), 32% PEG4000 or PEG3350 ). However the quality of the crystal is not so great,some of them look like needle cluster(very long in length), some of them look like multi-crystals or hollow inside. We tried to optimize the pH and PEG and tested one that diffracts at 2.9A. For the next, how to improve resolution?Any suggestions? Even mutate the protein to get a high resolution is ok, generally what kind of mutation would make proteins crystallize better? Thanks.
