Helix aspersa

About the Lectin

The commercially available edible snail found in the United States contains a lectin which is specific for GalNAc. Although HAA is most reactive with GalNAc it is also inhibited to some degree by GlcNAc. The lectin HAA is almost identical with regard to carbohydrate specificity when compared to Helix pomatia (HPA), although HAA seems to react more strongly with GlcNAc than HPA. Futhermore, monoclonal antibodies to HPA show only limited cross-reactivity to HAA. 1 Glucose by itself is not an inhibitor of HAA, even at a final concentration of 1.0M. HAA may be purified by many methods, including affinity chromatography on a dextran matrix 2 . Purified HAA is blood group A specific. Human type B erythrocytes may or may not react with the lectin, depending upon the method used for isolation of the glands and the age of the blood cells. Reactivity with type B erythrocytes requires the use of freshly collected blood cells. The isolation method used by EY Laboratories yields a lectin which does not react with type B erythrocytes. The procedure can be modified to obtain a purified lectin that will react with both A and B cells. EY Laboratories will prepare the lectin with dual binding specificities on request. Please contact technical services for information. HAA is sensitive to freeze-thaw cycles and lyophilization, both of which give rise to insoluble aggregates 2 .

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REFERENCES

  1. Schneider, HA. (1985) Zeitschrift fur Naturforschung. C. Biosciences. 40 : 254-261.
  2. Ishiyama, I., et al. (1972). Zeitschrift fur die Gesante Blutforschung. 24 : 178-179.

Product Characteristics

Buffer 0.01M Tris – 0.15M NaCl, pH 8.0 containing 5mM GlcNAc as a stabilizer.
Blood Group A1, A2.
Activity Less than 0.5 μg/ml will agglutinate A1 or A2 cells. Neuraminidase treated B and O cells react as strongly as type A cells.
Inhibitory Carbohydrate N-acetyl‑D‑galactosamine >> N‑acetyl‑D‑glucosamine.
Molecular Weight Not determined.
Caution Do not freeze!! Store refrigerated at 5-8°C.