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 lactose ligand is bound at the concave face of the β-sheet[5]. Water molecules shown as red spheres.
3D structures of galectin
Galectin 3D structures
- ↑ Barondes SH, Cooper DN, Gitt MA, Leffler H. Galectins. Structure and function of a large family of animal lectins. J Biol Chem. 1994 Aug 19;269(33):20807-10. PMID:8063692
- ↑ Barres C, Blanc L, Bette-Bobillo P, Andre S, Mamoun R, Gabius HJ, Vidal M. Galectin-5 is bound onto the surface of rat reticulocyte exosomes and modulates vesicle uptake by macrophages. Blood. 2010 Jan 21;115(3):696-705. doi: 10.1182/blood-2009-07-231449. Epub 2009, Nov 10. PMID:19903899 doi:https://dx.doi.org/10.1182/blood-2009-07-231449
- ↑ Liu FT, Rabinovich GA. Galectins: regulators of acute and chronic inflammation. Ann N Y Acad Sci. 2010 Jan;1183:158-82. doi: 10.1111/j.1749-6632.2009.05131.x. PMID:20146714 doi:https://dx.doi.org/10.1111/j.1749-6632.2009.05131.x
- ↑ Radosavljevic G, Volarevic V, Jovanovic I, Milovanovic M, Pejnovic N, Arsenijevic N, Hsu DK, Lukic ML. The roles of Galectin-3 in autoimmunity and tumor progression. Immunol Res. 2012 Apr;52(1-2):100-10. doi: 10.1007/s12026-012-8286-6. PMID:22418727 doi:https://dx.doi.org/10.1007/s12026-012-8286-6
- ↑ Lopez-Lucendo MF, Solis D, Andre S, Hirabayashi J, Kasai K, Kaltner H, Gabius HJ, Romero A. Growth-regulatory human galectin-1: crystallographic characterisation of the structural changes induced by single-site mutations and their impact on the thermodynamics of ligand binding. J Mol Biol. 2004 Oct 29;343(4):957-70. PMID:15476813 doi:https://dx.doi.org/10.1016/j.jmb.2004.08.078