Description of a monomeric prototype galectin from the lizard Podarcis hispanica

Galectins are a continuously expanding family of beta -galactoside-binding lectins present in a variety of evolutionarily divergent animal species. He re we report, for the first time, that expression of galectins extends to t he reptilia lineage of lizards. Up to five lactose-binding proteins were is olated from the lizard Podarcis hispanica by affinity chromatography on asi alofetuin-Sepharose, The main component, which is most abundantly expressed in skin, was purified from this tissue and further characterized. Under na tive conditions the protein behaved as a monomer with a molecular mass of 1 4,500 Da and an isoelectric point of 6.3, Based on sequence homology of the 58 N-terminal amino acid residues with galectins, and on its demonstrated galactoside-binding activity, this lectin we named LG-14 (from Lizard Galec tin and 14 kDa) is classified as a new member of the galectin family. LG-14 falls into and strengthen the still thinly populated category of monomeric prototype galectins.