MP20/galectin-3 complex formation in vitro . (A) SDS-PAGE analysis of pure MP20 and pure galectin-3 and of the complex formed. Lane 1. Molecular weight markers. Lanes 2 and 3. Pure MP20 and galectin-3 used for the binding experiment, respectively. Lane 4. The complex eluted from the gel filtration column. Galectin-3 appears as a doublet due to minor proteolysis . (B) Size exclusion chromatography of MP20/galectin-3 complexes formed following the mixing of purified lens MP20 with purified galectin-3. The complex eluted at 13 ml. mAU refers to absorbance units at 280 nm. (C) Calibration of the S-200 column. Vo = 7.8 ml. MP20/galectin-3 complex has an apparent molecular mass of 104 kDa (arrow).