Intan M. Maliki1, Wilson T.L. Yong1,2, Mailin Misson1, Peik Lin Teoh1
1Biotechnology Research Institute, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia.
2Seaweed Research Unit, Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia.
Numerous red algae species possess lectins with carbohydrate specificity towards complex glycoproteins or high-mannose N-glycans, eliciting biochemical responses such as antiviral, anticancer, and antibacterial activity, making them appealing tools in biomedical research. Kappaphycus alvarezii, a marine red alga, was collected from the coast of Semporna, Sabah, Malaysia. The collected sample was further cultivated in the Biotechnology Research Institute, Universiti Malaysia Sabah, in filtered seawater and with Provasoli’s solution as its nutrient media, with pH 8.60-8.80 and salinity between 35-45 ppt. The crude protein from K. alvarezii was extracted by incubating it in a phosphate buffered saline (PBS) buffer, pH 7.0, overnight at 4°C. The sample was then homogenized in PBS buffer and precipitated to 85% using ammonium sulfate precipitation. The extracted crude protein was separated on SDS-PAGE with b-mercaptoethanol to detect the presence of putative lectin on the gel with an expected band size before being purified using a GalNAc-specific column. The purification was performed on a Sepharose 6B~GalNAc affinity column, and the peak appeared following the addition of elution buffer (0.85% NaCl with lactose). Hemagglutination assay performed on peak fractions capable of agglutinating mice erythrocytes treated with papain, showing probable lectin activity of the purified protein.