Revealing protein structures: crystallization of protein‐ligand complexes – co‐crystallization and crystal soaking

Abstract

Protein crystallogenesis represents a key step in X‐ray crystallography studies that employ co‐crystallization and ligand soaking for investigating ligand binding to proteins. Co‐crystallization is a method that enables the precise determination of binding positions, although it necessitates a significant degree of optimization. The utilization of microseeding can facilitate a reduction in sample requirements and accelerate the co‐crystallization process. Ligand soaking is the preferred method due to its simplicity; however, it requires careful control of soaking conditions to ensure the successful integration of the ligands. This research protocol details the procedures for co‐crystallization and soaking to achieve protein–ligand complex formation, which is essential for advancing drug discovery. Additionally, a simple protocol for demonstrating soaking for educational purposes is described.