Growth inhibition of protein crystals: A study of lysozyme polymorphs   
Author(s): Heijna MCR, van Enckevort WJP , Vlieg E
Cryst. Growth & Des. 8 no. 1 (2008) 270-274
     
Abstract:
Crystal morphology is determined by the relative growth rates of the different faces involved. Opposite faces (hkl) and (hkl) can show different rates if the crystal structure does not have inversion symmetry. Protein crystals, being built of asymmetric molecules, do not have identical opposite faces, except for those pairs linked by rotational symmetry. Here, we present an in situ microscopy study on the polar growth of various polymorphs of hen egg-white lysozyme crystals. It was found that in a number of cases the growth of one of the two faces was blocked, whereas the opposite one was not slowed down. To explain our results, we propose a self-poisoning mechanism based on solvent-induced adsorption of misorientated lysozyme molecules on the inhibited faces. This mechanism can also prevent some proteins from forming crystals at all.