Osaka University team uses Zetasizer Nano for protein screening

A research team in Japan has published work that illustrates the utility of Malvern Instruments’ Zetasizer Nano particle characterization system in assessing the suitability of a protein sample for crystallization.

While protein crystallization is a prerequisite for molecular structure determination using X-ray diffraction techniques, it is a time-consuming activity that traditionally involves screening many different buffer conditions to define the ideal.

Studies to assess the role of the Zetasizer Nano in this screening process were carried out at the Institute of Protein Research at Osaka University (Professor Nakagawa’s group), in conjunction with Maruwa Food Industries and the Sysmex Corporation of Japan. Measurement of particle size by dynamic and static light scattering methods is known to be an effective method in the evaluation of whether or not a sample is suitable for crystallization. The Zetasizer Nano uses both static and dynamic light scattering techniques, and incorporates unique non-invasive back scatter (NIBS) technology. The studies focused on the use of this system to assess the condition of protein solutions.

The results indicated that the application of back scatter technology in the Zetasizer Nano enables the quality of proteins at low concentrations around 0.1 mg/ml following chromatography to be assessed. Importantly the system can be used equally well for screening proteins for crystallography at very high concentrations of around 100 mg/ml. The researchers concluded that the system enables characterization both of the protein sample before concentration and at the very high concentrations seen close to crystallization.

The results were presented at the Annual Meeting of the Crystallographic Society of Japan in Himeji on 6/7 December 2005.