Chapter 2 - Crystallography and Lectin Structure Database

Abstract

Lectins comprise a very diverse group of carbohydrate-binding proteins of non-immune origin proteins, which come in many different sizes and folds. Several methods exist that allow the detailed three-dimensional characterization of protein structures and their ligand complexes, such as NMR, X-ray crystallography, neutron diffraction, and electron microscopy. X-ray crystallography relies on the diffraction of X-rays by the electrons of the atoms. Protein crystals are a necessary precondition for the study of proteins or protein ligand complexes by this method. X-ray crystallography of purified lectins in complex with saccharides can provide high-resolution structural data and a visual tool to probe protein—carbohydrate interactions. X-ray crystallography is particularly powerful in terms of the range of problems that can be studied (from small molecules to huge protein complexes such as the ribosome) and the atomic precision that is obtained. This chapter introduces to X-ray crystallography as an analytical techniques that can be applied to the characterization of new or existing lectins, or the use of lectins as analytical tools.