Identification of galectin-3 as a high-affinity binding protein for advanced glycation end products (AGE): a new member of the AGE-receptor complex

Mol Med. 1995 Sep;1(6):634-46.


Background: Advanced glycation end products (AGE), the reactive derivatives of nonenzymatic glucose-protein condensation reactions, are implicated in the multiorgan complications of diabetes and aging. An AGE-specific cellular receptor complex (AGE-R) mediating AGE removal as well as multiple biological responses has been identified. By screening an expression library using antibody against a previously identified component of the AGE-R complex p90, a known partial cDNA clone was isolated with homology to galectin-3, a protein of diverse identity, and member of the galectin family.

Materials and methods: To explore this unexpected finding, the nature of the interactions between galectin-3 and AGE was studied using intact macrophage-like RAW 264.7 cells, membrane-associated and recombinant galectin-1 through -4, and model AGE-ligands (AGE-BSA, FFI-BSA).

Results: Among the members of this family (galectin-1 through 4), recombinant rat galectin-3 was found to exhibit high-affinity 125I-AGE-BSA binding with saturable kinetics (kD 3.5 x 10(7) M-1) that was fully blocked by excess unlabeled naturally formed AGE-BSA or synthetic FFI-BSA, but only weakly inhibited by several known galectin-3 ligands, such as lactose. In addition to the p90, immunoprecipitation with anti-galectin-3, followed by 125I-AGE-BSA ligand blot analysis of RAW 264.7 cell extracts, revealed galectin-3 (28 and 32 kD), as well as galectin-3-associated proteins (40 and 50 kD) with AGE-binding activity. Interaction of galectin-3 with AGE-BSA or FFI-BSA resulted in formation of SDS-, and beta-mercaptoethanol-insoluble, but hydroxylamine-sensitive high-molecular weight complexes between AGE-ligand, galectin-3, and other membrane components.

Conclusions: The findings point toward a mechanism by which galectin-3 may serve in the assembly of AGE-R components and in the efficient cell surface attachment and endocytosis by macrophages of a heterogenous pool of AGE moieties with diverse affinities, thus contributing to the elimination of these pathogenic substances.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antibodies, Monoclonal
  • Antigens, Differentiation / analysis
  • Antigens, Differentiation / isolation & purification
  • Antigens, Differentiation / metabolism*
  • Binding, Competitive
  • Carrier Proteins / metabolism
  • Cell Line
  • Electrophoresis, Polyacrylamide Gel
  • Enzyme-Linked Immunosorbent Assay
  • Galectin 3
  • Glycation End Products, Advanced / metabolism*
  • Immunoblotting
  • Iodine Radioisotopes
  • Kinetics
  • Liver / metabolism
  • Macrophages
  • Membrane Glycoproteins / metabolism
  • Mice
  • Molecular Weight
  • Radioligand Assay
  • Rats
  • Receptor for Advanced Glycation End Products
  • Receptors, Immunologic / analysis
  • Receptors, Immunologic / isolation & purification
  • Receptors, Immunologic / metabolism*
  • Recombinant Proteins / analysis
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism


  • Antibodies, Monoclonal
  • Antigens, Differentiation
  • Carrier Proteins
  • Galectin 3
  • Glycation End Products, Advanced
  • Iodine Radioisotopes
  • Membrane Glycoproteins
  • Receptor for Advanced Glycation End Products
  • Receptors, Immunologic
  • Recombinant Proteins