Solution and in silico studies on the recombinant lectin from Cicer arietinum seeds

► Cloning and expression of the plant lectin gene into active protein in Escherichia coli. ► Thermo-labile protein showing rapid structural changes from 50 to 55°C. ► Unfolding followed by dissociation of the dimer in presence of GdnHCl. ► Reorientation of trp microenvironment in low concentration of GdnHCl. ► Experimental results correlate well with the homology model. The Cicer arietinum seed lectin was cloned and expressed in Escherichia coli and purified in active form. Conformational characterization of the recombinant lectin (rCAL) was performed using biophysical and bioinformatics tools. Thermal denaturation of rCAL caused rapid secondary structural rearrangements above 50°C and transient exposure of hydrophobic residues at 55°C, leading to aggregation. Treatment of rCAL with GdnHCl resulted in unfolding followed by dissociation of the dimer. The single tryptophan in rCAL present on the surface of the protein is surrounded by hydrophobic and acidic amino acids and exists as different conformers. The experimental observations correlated well with the structural information revealed from the homology model of rCAL.