ABSTRACT
Galectins are an ancient family of animal lectins present in phylogenically distant organisms de ned by selectivity for β-galactose and the presence of consensus amino-acid sequences [1]. Family members are observed in vertebrates, insects, nematodes, fungi and marine sponges, and homologs are present in plants [2] and viruses [3]. Fifteen members are described in mammals and others are present in expression databases [2]. The conserved galectin carbohydrate recognition domain (CRD) consists of approximately 130 amino acids that provide lectin activity. Family members contain a single CRD domain (galectin-1, -2, -5, -7, -10, -11, -13, -14, and -15) or two domains linked by a nonconserved peptide (galectin-4, -6, -8, -9, and -12). Galectin-3 is the only member of the third form with a single CRD domain and N-terminal region of approximately 120 amino acids composed of tandem repeats of short amino-acid segments.
