Nucleating Agent Crystallophore Induces Instant Protein Crystallization
C. Sauter, Dominique Housset, Julien Orlans, Raphaël de Wijn, K. Rollet, Samuel L. Rose, Shibom Basu, Philippe Bénas, Javier Pérez, Daniele de Sanctis, Olivier Maury, Éric Girard
Abstract
The rapid preparation of homogeneous suspensions of micro- or nanocrystals is a crucial step in serial crystallography. We show how additives, such as the crystallophore (TbXo4) that acts as a molecular glue by promoting protein–protein interactions, can facilitate sample preparation for both serial synchrotron crystallography (SSX) and micro electron diffraction (3D ED). This lanthanide complex was used here for its nucleating properties to crystallize the hen egg-white lysozyme. SAXS monitoring indicates that crystals grew in a few minutes under low salt conditions, which would not lead to spontaneous nucleation in the absence of TbXo4. Resulting micro- and nanocrystals were successfully used to determine the structure of the lysozyme-TbXo4 complex by SSX and 3D ED, illustrating the diffraction quality of the produced crystals and the usefulness of such compounds in the sample preparation pipeline for serial crystallography.