Peanut Agglutinin (PNA), Unconjugated

Peanut lectins preferentially bind to the t antigen, a galactose (beta-1,3) n-acetylgalactosamine structure found in many glycoconjugates, such as the M and N blood groups, gangliosides, and many other soluble and membrane-associated glycoproteins and glycolipids. With some exceptions, PNA receptor sequences are often sialized, which prevents the binding of lectins to their receptor oligosaccharides (see Jacalin). Even sialic acids that do not directly bind to the receptor sugars may inhibit this binding. The presence of calcium ions in the diluent can enhance PNA binding to the receptor, possibly by neutralizing the negative charge on sialic acid residues close to the receptor sequence.