About the Lectin
The carbohydrate specificity of LAA is not completely understood. LAA agglutinates neuraminidase-treated human O(H) cells more strongly than A or B cells. The anti O(H) lectin has been resolved into two isolectins, LAA-I and LAA-II. 1 Although LAA-I is inhibited by di-N-acetylchitobiose and LAA-II by lactose or phenyl-β-galactoside, both isolectins require the α-fucosyl residue on the O(H) erythrocytes. 1 The amino acid sequence of LAA-I has been determined; 2 it shows 50-80% homology with other legume lectins, with the metal-binding site and putative carbohydrate-binding site highly conserved.
Techniques developed by EY Laboratories have produced a partially purified lectin which is suitable for labeling purposes. The partially purified mixture of isolectins binds to specific subtypes of cells in various meningiomas, proving to be useful, along with other lectins, in histological investigations of these tumors. 3
- Konami, Y., et al. (1983) Hoppe-Seylers Z. Physiol. Chem. 364 : 397-405.
- Konami, Y., et al. (1991) FEBS Lett. 286 : 33-38.
- Kleinert, R. and Radner, H. (1987) Neuropath. Appl. Neurobiol. 13 :263-272.
|Buffer||0.01M Phosphate – 0.15M NaCl, pH 7.2-7.4.|
|Activity||At least 60 μg/ml is necessary in order to exhibit visual agglutination with type O human erythrocytes. Only 2 μg/ml is required to agglutinate neuraminidase treated red blood cells.|
|Inhibitory Carbohydrate||N‑acetyl‑D‑glucosamine (nominally), LAA-I. β-Galactosides, LAA-II.|
|Molecular Weight||110,000 (LAA-I), 78,000 (LAA-II).|