Function
Galectin or galactoside-binding soluble lectin (GAL) are lectins which bind β-galactosidase (BGAL). GAL contains a carbohydrate recognition domain (CRD) residues 113-250[1].
- GAL-1 is thought to play a role as autocrine negative growth factor that regulates cell proliferation.
- GAL-2 is expressed primarily in gastrointestinal tract.
- GAL-3 has broad biological functionality.
- GAL-4 has 2 CRDs.
- GAL-5 is found in rat is a β-galactoside binding lectin[2].
- GAL-7 is associated with epithelial cells.
- GAL-8 has a role in cellular defense against bacterial infection and vacuolar damage.
- GAL-9 affects eosinophil survival.
- GAL-10 or Charcot-Leyden crystal protein acts on biological membranes to regulate the multifunctional lysophospholipids.
- GAL-13 is a placental protein which does not bind β-galactosides.
Relevance
GAL are known to inhibit chronic inflammation[3]. GAL-3 has a role in experimental autoimmune encephalomyelitis and melanoma methastasis[4].
Structural highlights
The CRD is a β-sandwich long enough to bind a tetrasaccharide. A [5]. Water molecules shown as red spheres.
3D structures of galectin
Galectin 3D structures