Expression, Purification and Characterization of Human Recombinant Galectin 3 in Pichia pastoris

Background: Over the past century, the areas of genomics, proteomics and lipids have captured the attention of investigators worldwide. Carbohydrates, have recently received increased attention through the expanding field of glycobiology; probably because they are very complex and not encoded in the genome. Objectives: The purpose of this study was to express and purify recombinant human galectin 3via the Pichiapastoris expression system. Materials and Methods:cDNA of human galectin 3 gene was amplified with specific primers and cloned into a pcDNA3.1 vector with His-tag for easier purification using Ni2andchromatography. Furthermore, galectin 3was purified to homogeneity and confirmed using SDS-PAGE and western blotting. Results:The protein band corresponding to 29 kDa was excised from the gels, digested with trypsin and processed for mass spectrometric analysis by Matrix Assisted Laser Desorption/Ionization- Time of Flight Mass Spectroscopy (MALDI-TOF MS), using a Reflex III instrument. Conclusions:Tryptic digest analysis clearly revealed that the purified protein was indeed galectin 3. Similarly, the biological activity of recombinant galectin 3 was confirmed using the hemagglutination inhibition assay.