Arachis hypogaea (PNA, Peanut Agglutinin)

Peanut agglutinin is a 110,000 molecular weight lectin composed of four identical subunits of approximately 27,000D each. PNA binds preferentially to a commonly occurring structure, galactosyl (b-1,3) N-acetylgalactosamine. This carbohydrate sequence (called the “T-antigen”) is present in many glycoconjugates such as M and N blood groups, gangliosides, and many other soluble and membrane-associated glycoproteins and glycolipids. With certain exceptions, the receptor sequence for PNA is normally sialylated which prevents the lectin from binding to its receptor oligosaccharide (see Jacalin). In fact, even sialic acid which is not bound directly to the receptor sugars may inhibit binding. Although PNA appears not to require any divalent cations for activity, the presence of calcium ions in diluents can enhance the binding of PNA to receptors, possibly by neutralizing the negative charges on sialic acid residues adjacent to the receptor sequence. PNA is useful in distinguishing between normal and tumor tissues and in assessing malignancy in transitional mucosa. In addition, PNA binding has been employed as a measure of cellular maturity in lymphoid tissues, to distinguish a variety of lymphocyte subpopulations in man and experimental animals, and to measure the levels of lymphoid cell populations in many diseases. PNA has been employed in the fractionation of stem cells in mice for use in bone marrow transplantation across histocompatibility barriers. A major cell surface receptor for PNA may be asialo GM1 ganglioside. Since PNA shares specificity with the antibody to this glycolipid, PNA and the antibody can be used interchangeably in some applications.

Applications:
Suitable for use in ELISA. Other applications not tested.

Recommended Dilutions:
Optimal dilutions to be determined by the researcher.

Storage and Stability:
Lyophilized powder may be stored at -20°C. Stable for 12 months at -20°C. Reconstitute with sterile 10mM HEPES buffered saline, pH 8.5, 0.1mM Ca++. Aliquot to avoid repeated freezing and thawing. Store at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.