Obtaining well diffracting crystals and
solving protein structure can be tedious work and successful process may
include various crystallization techniques and tricks. Here we present one
didactic story of crystallization a-L-Rhamnosyl-b-D-glucosidase (Rutionsidase) from Aspergilus niger. During the crystallization process, we performed
screening using vapour diffusion method, optimization by counter diffusion
technique, and final crystals soaking of heavy atoms in micro batch
experiments, which allowed structure solution by SIRAS. However, to repeat the
crystal growth, we had to deglycosylate the enzyme
and perform new screening followed by Matrix Microseed
Screening. Moreover, as final reproducible procedure, for growing the protein
crystals, we used under oil micro batch experiments. With this optimised
method, we were able to grow crystal that diffracted up to 1.27 Å
resolution and see structural details that shall be used in the future.