Galectin

In molecular biology, galectins (also known as galaptins or S-lectin) are a family of lectins which bind beta-galactoside. The family is defined by having at least one characteristic carbohydrate recognition domain (CRD) with an affinity for beta-galactosides and sharing certain sequence elements. Members of the galectin family are found in mammals, birds, amphibians, fish, nematodes, sponges, and some fungi. Galectins are known to carry out intra- and extracellular functions, including inhibition of chronic inflammations, GVHD, and allergic reactions, through glycoconjugate-mediated recogntion. From the cytosol they may be secreted by non-classical pathways, but they may also be targeted to the nucleus or specific sub-cytosolic sites. Within the same peptide chain some galectins have a CRD with only a few additional amino acids, whereas others have two CRDs joined by a link peptide, and one (galectin-3) has one CRD joined to a different type of domain.

Genes encoding galectin include:


 * (see also LGALS3)
 * (see also LGALS3)
 * (see also LGALS3)

Structure
The galectin carbohydrate recognition domain (CRD) is a beta-sandwich of about 135 amino acid. The two sheets are slightly bent with 6 strands forming the concave side and 5 strands forming the convex side. The concave side forms a groove in which carbohydrate is bound, and which is long enough to hold about a linear tetrasaccharide.