Isolation and Purification of Lectin-like Protein from Terminalia catappa Seeds Using Combination of Chromatographic Techniques

Lectins are a wide group of proteins found in plants, animals, and marine organisms. These proteins are characterized by their remarkable ability to bind carbohydrates, playing critical roles in various biological processes, such as cell recognition, immune response, and pathogen defense. Plant-derived lectins, in particular, have shown significant medicinal potential, including antifungal, antiviral, and anti-inflammatory properties. However, to fully harness the therapeutic benefits of plant lectins, efficient extraction and purification techniques are essential. Terminalia catappa, commonly known as the tropical almond tree, has been used in traditional medicine for various therapeutic purposes, including antimicrobial, anti-inflammatory, antitumor, and antioxidant effects. The seeds of this plant contain bioactive compounds, among which lectins play a crucial role. It has been reported that lectins are glycoproteins exhibiting specificity towards certain carbohydrate moieties. This property is made use of in the purification of lectins and other glycoproteins using the technique of affinity chromatography. Due to the presence of sugar residues, lectins can demonstrate hemagglutination activity. This study aimed to isolate and purify lectin-like proteins from the seeds of the medicinally important Terminalia catappa plant. Lectin was isolated using phosphate-buffered saline (PBS) and purified through a series of steps including ammonium sulfate precipitation, dialysis, gel filtration, and affinity chromatography. The saline extract had a protein concentration of 1.5mg/ml, while after performing gel filtration and affinity chromatography, the concentration was found to be 0.9 mg/ml and 0.7mg/mL, respectively. A single peak obtained on the affinity column indicated the lectin’s homogeneous form with a simultaneous increase in the specific activity of the lectin.