Functional and structural bases of a cysteine-less mutant as a long-lasting substitute for galectin-1

Glycobiology. 2008 Dec;18(12):1065-73. doi: 10.1093/glycob/cwn089. Epub 2008 Sep 16.


Galectin-1 (Gal-1), a member of the beta-galactoside-binding animal lectin family, has a wide range of biological activities, which makes it an attractive target for medical applications. Unlike other galectins, Gal-1 is susceptible to oxidation at cysteine residues, which is troublesome for in vitro/vivo studies. To overcome this problem, we prepared a cysteine-less mutant of Gal-1 (CSGal-1) by substituting all cysteine residues with serine residues. In the case of wild-type Gal-1, the formation of covalent dimers/oligomers was evident after 10 days of storage in the absence of a reducing agent with a concomitant decrease in hemagglutination activity, while CSGal-1 did not form multimers and retained full hemagglutination activity after 400 days of storage. Frontal affinity chromatography showed that the sugar-binding specificity and affinity of Gal-1 for model glycans were barely affected by the mutagenesis. Gal-1 is known to induce cell signaling leading to an increase in the intracytoplasmic calcium concentration and to cell death. CSGal-1 is also capable of inducing calcium flux and growth inhibition in Jurkat cells, which are comparable to or more potent than those induced by Gal-1. The X-ray structure of the CSGal-1/lactose complex has been determined. The structure of CSGal-1 is almost identical to that of wild-type human Gal-1, showing that the amino acid substitutions do not affect the overall structure or carbohydrate-binding site structure of the protein. These results indicate that CSGal-1 can serve as a stable substitute for Gal-1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Substitution
  • Binding Sites
  • Cell Proliferation
  • Crystallography, X-Ray
  • Cysteine / genetics*
  • Cysteine / metabolism
  • Galectin 1 / chemistry*
  • Galectin 1 / genetics*
  • Galectin 1 / metabolism
  • Humans
  • Jurkat Cells
  • Membrane Glycoproteins / metabolism
  • Models, Molecular
  • Mutagenesis, Site-Directed
  • Mutation*
  • Oxidation-Reduction
  • Protein Conformation
  • Structure-Activity Relationship


  • Galectin 1
  • Membrane Glycoproteins
  • Cysteine