About the Lectin
The seeds of the South American coral tree contain a lectin that agglutinates human erythrocytes and is mitogenic for human and Rhesus monkey peripheral T cells 1 . It is a glycoprotein containing Mn ++ and Ca ++ . The closely related E. corallodendron contains a nearly identical lectin, EcorL. The carbohydrates specificity of these lectins have been studues in detail 2,3 . Their primary reactivity is with terminal LacNAc structures, Galβ1,4GlcNAc. The 2’ fucosylated derivative is also reactive, but other substitutions, including sialylation, are not tolerated. Glycolipids containing these groups are bound, as demonstrated by specific binding of the lectin to specific bands on thin layer chromatograms of pure or mixed glycolipids. Also, the lectins agglutinate guinea pig erythrocyte 5 coated with LacNAc-containing glycosylceramides, whereas untreated erythrocytes from this species are not agglutinated 4 . ECA is one of the first lectins shown to be specific for the LacNAc structure 5 , a major component of most N-linked glycoproteins 6 . It is also reactive, to a lesser degree, with GalNAc and weaker still with galactose 7 . ECA has been reported to bind specifically to immature thymocytes and to undifferentiated teratocarcinama cells, but not to the differentiated cells 8 . Similarly, both ECA and EcorL show much greater binding to gastrointestinal carcinomas than to corresponding normal tissue 9 . ECA has also been applied to enrich a population of peripheral blood mononuclear cells in natural killer cells 10 .
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- Debray, H., et al. (1986) Carbohydr. Res. 151 : 359-370.
- Teneberg, S., et al. (1994) J. Biol. Chem. 269 : 8554-8563.
- Lis, H., et al. (1985) Phytochemistry 24 : 2803.
- Crowley, J. F. and Goldstein, I. J. (1981) FEBS Lett. 130 : 149-152.
- Lis. H. and Sharon, N. (1987) Meth. Enzynol. 138: 544.
- Webb, C. W., et al. (1985) in “Cell Membranes and Cancer”.Galeotti, T., et al. Eds. Page 13. Elsevier, Amsterdam.
- Baldus, S.E., et al. (1996) Int. J. Oncol. 9 : 43-48.
- Harris, D.T., et al. (1987) J. Leukocyte Biol. 42 : 163-170.
|Buffer||0.01M Phosphate – 0.15M NaCl, pH 7.2-7.4|
|Blood Group||Nonspecific. ECA reacts stronger with neuraminidase treated human erythrocytes.|
|Activity||1-2 μg/ml will agglutinate neuraminidase treated human erythrocytes.|
|Inhibitory Carbohydrate||N-acetyllactosamine > Lactose > N‑acetyl‑D‑galactosamine > Galactose|
|Molecular Weight||Aggregate MW=56,800. A single band of MW=28-30,000 by SDS-PAGE.|