1965 - Hen-egg-white lysozyme (PDB file 1lyz).[8] was the first crystal structure of an enzyme (it cleaves small carbohydrates into simple sugars), used for early studies of enzyme mechanism.[9] It contained beta sheet (antiparallel) as well as helices, and was also the first macromolecular structure to have its atomic coordinates refined (in real space).[10] The starting material for preparation can be bought at the grocery store, and hen-egg lysozyme crystallizes very readily in many different space groups; it is the favorite test case for new crystallographic experiments and instruments. Recent examples are nanocrystals of lysozyme for free-electron laser data collection[11] and microcrystals for micro electron diffraction.[12]