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Featuring:
Plus
quality reagents for:
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| Agarose Bound* Peanut Agglutinin (PNA)
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Peanut agglutinin binds preferentially to the T-antigen, a galactosyl
(β-1,3) N-acetylgalactosamine structure 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). Even sialic acid which is not bound directly to the
receptor sugars may inhibit binding. 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 can be used to measure 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 can be 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.
Agarose bound* PNA is prepared using our affinity-purified
lectins. Heat stable, cross-linked 4% agarose beads with
a molecular weight exclusion limit of about 2x107 daltons
are used as the solid-phase matrix to which the lectins are
covalently coupled. The attachment of the lectins to the beads
is carefully controlled to preserve lectin activity and minimize
conformational changes of the bound lectins that might result
in nonspecific ionic or hydrophobic interactions. The technique
we have developed to couple lectins to agarose beads inserts a
hydrophilic spacer arm between the lectin and the matrix.
This coupling method provides several advantages over the
traditional cyanogen bromide procedure:
Maximum carbohydrate binding activity of the coupled
lectins is retained
Linkage is stable over a range of pH values
Conjugated proteins are not leached off the beads by Tris or
other routinely used buffers
No residual charges are present after conjugation. This
minimizes non-specific binding to the matrix.
Our agarose bound lectins are supplied at a constant
concentration of lectin per ml of settled beads. The
concentration for each lectin is selected to achieve the highest
glycoconjugate binding capacity per mg of lectin present in
the beads. Each lot is tested for its binding capacity using
glycoproteins known to bind the lectin. This provides a
guideline for the user and assures the quality of our agarose
bound lectins.
Inhibiting/Eluting Sugar: 200 mM galactose
* 5 mg lectin/ml gel
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