Purification and characterization of serum α₂-globulin binding protein from <i>Alocasia macrorhiza </i>tuber

Abstract

A protein capable of precipitating serum α₂-globulin was purified from <i>Alocasia macrorhiza </i>tuber. The protein, designated as Alocasia protein was heat labile and was found to exist in four isomeric forms, each having four subunits. The serum α₂-globulin binding activity of the Alocasia protein was not altered by the action of proteolytic enzymes like trypsin, chymotrypsin and pepsin .Unlike the naturally occurring lectins, the Alocasia protein failed to agglutinate erythrocytes, leukocytes and the microbial organisms. In addition, different

sugars and sugar derivatives did not prevent the complex formation between the Alocasia protein and α₂-globulin of serum. Divalent metal ions and SH agents did not affect the activity of the protein. Preliminary<i> </i>studies indicated that haptoglobin and α₂-macroglobulins were the major, if not the exclusive proteins that are<i> </i>responsible for interaction with the purified Alocasia protein.