Protein crystallization is the act and method of creating structured, ordered lattices for complex macromolecules. Proteins are typically amorphous as solids and prone to denaturation, whereas proteins existing in crystalline lattices resist denaturation and possess greater stability. Proteins can crystallize if placed in suitable, hospitable environments. Protein crystallization is viewed as much as an art as a science, due to the highly complex interactions of variables that influence the protein crystallization process.
The most common reason for creating protein crystals is to support structural biology investigations, typically via x-ray diffraction crystallography. Investigators can visualize areas in the framework that permit interaction with other molecules by understanding the 3-dimensional structures of proteins (for example, to better understand how enzymes, substrates and ligands interact). Furthermore, crystallization is an effective means of creating pure proteins that are free of contamination from other proteins or extraneous biological matter, thus offering an alternative means of purification and separation to preparative chromatography.