Electron diffraction of protein 3D nanocrystals

Abstract

Protein crystallography, being one of the most established methods for structure determination of biomacromolecules, relies on the diffraction analysis using X-rays for 3D (micro-)crystals. Electron diffraction is only employed for single layer 2D nano-crystals. However, there is no established method for analysing multi-layered 3D nano-sized protein crystals. Electron diffraction may fill this important niche, but several problems have to be surmounted for this method to become mainstream. Our group aims tackling some of the bottlenecks, and although our work is still very much in progress, we can report advances in some important areas. Here we summarise improvements in (i) the induction of growth of (nano-)crystals, (ii) electron diffraction data collection using the Medipix quantum area detector, (iii) unit cell determination using single, non- oriented diffraction patterns, (iv) integration of diffraction data and (v) phasing of electron diffraction data. © 2012 Springer Science+Business Media Dordrecht.