Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of the N-terminal carbohydrate-recognition domain of human galectin-4

Galectin-4 is a tandem-repeat-type galectin that is expressed in the epithelium of the alimentary tract from the tongue to the large intestine. Additionally, strong expression of galectin-4 can also be induced in cancers in other tissues, including the breast and liver. In order to explore its potential as a target for anticancer drug design, elucidation of the structural basis of the carbohydrate-binding specificities of galectin-4 has been focused on. As an initial step, the N-terminal carbohydrate-recognition domain of human galectin-4 (hGal4-CRD-1) has been successfully crystallized using the vapour-diffusion technique, a complete data set has been collected to 2.2 angstrom resolution and the structure has been solved by the molecular-replacement technique. The crystals belonged to space group P6(1)22, with unit-cell parameters a = b = 71.25, c = 108.66 angstrom. The asymmetric unit contained one molecule of hGal4-CRD-1, with a V-M value of 2.34 angstrom(3) Da(-1) and a solvent content of 47.51%.