Fig. 6

Recombinant Galectin-1 hydrodynamic characterization discloses its instability. a Analytical ultracentrifugation shows that wild-type Galectin-1 purified in non-reducing conditions sediments as a mixture of monomer, dimer, and various disulfide-crosslinked oligomeric species (purple curve). In contrast, purification in reducing conditions yields the expected non-covalent dimer (blue curve), which can also be revived from the oxidized sample by transferring it to the reducing conditions (cyan curve). However, the cysteine-less mutant of Galectin-1 is perfectly stable in non-reducing conditions and sediments solely as the expected non-covalent dimer. b SEC analysis of wild-type and cysteine-less Galectin-1 purified in non-reducing and reducing conditions complementing the AUC data. Apart from being freshly reduced, wild-type Galectin-1 is not monodisperse, even when purified in reducing conditions where self-oxidation still slowly occurs upon storage. On the contrary, the cysteine-less mutant is perfectly monodisperse in non-reducing conditions. (Original figure from Vaněk’s lab)