Homarus americanus

About the Lectin

Sialic acid specific lectins have been discovered in several invertebrates as well as in some plants, however, in plants this is often a secondary specificity or the sialic acid must have a specific linkage. The hemolymph of the lobster contains multiple agglutinins, two of which have been purified 1 . The lectins, referred to as LAg-1 and LAg-2, have different binding specificities. LAg-1 is specific for sialic acid (N-acetylneuraminic acid; NANA), while LAg-2 is specific for N-acetyl-D-galactosamine 2 . HMA agglutinating activity is greatest at 4°C between pH 7.5-8.0. Lectin activity decreases as the temperature increases and activity is irreversibly lost below pH 5.0. LAg-1 has been used to isolate a subpopulation of low-sialic acid, immature mouse thymocytes. 3 The purified lectin and corresponding conjugates are not always readily available. Contact EY Laboratories for further information.

REFERENCES

  1. Hall, J. L. and Rowlands, D. T., Jr. (1974). Biochemistry.13 : 821- 827.
  2. Hall, J. L. and Rowlands, D. T., Jr. (1974). Biochemistry.13 : 828- 832.
  3. Stedman, K. E., et al. (1990) Immunology 70 : 478-484.

Product Characteristics

Buffer 0.05M Tris – 0.15M NaCl – 0.01M CaCl2, pH 7.5‑8.0.
Blood Group B > O > A2.
Activity Less than 2.5 μg/ml will agglutinate human type B erythrocytes. At least 10 μg/ml is required to agglutinate type O or A2 erythrocytes.
Inhibitory Carbohydrate N-acetylneuraminic acid, N‑acetyl‑D‑galactosamine.
Molecular Weight Subunit MW=55,000 as determined by dissociation in 6M urea.
Caution HMA has a binding optimum at pH 7.5-8.0. Lectin activity is irreversibly lost below pH 5.0. HMA requries the addition of calcium to the working buffer. The lectin is most active at 4&#176C.