Promotion of Crystal Nucleation of Protein by Semi-Solid Agarose Gel

We investigate the nucleation rate of protein crystals in the presence of agarose gel at concentrations between 0.0 and 2.0% (w/v). It was found that agarose gel promoted the number of protein crystals up to a concentration of 0.4% (w/v), and gel at concentrations between 0.4 and 0.8% (w/v) decreased the nucleation rate. However, the number of crystals increased again in the presence of agarose by more than 1.0% (w/v), demonstrating high gel strength and a semi-solid gel. We propose that a crystallization method using semi-solid agarose is powerful for the screening of crystallization conditions. (C) 2009 The Japan Society of Applied Physics DOI: 10.1143/APEX.2.125501