Isolation and characterization of a lectin from the snail Biomphalaria glabrata and a study of its combining site - Bretting, H.; Stanislawski, E.; Jacobs, G.; Becker, W. (Elsevier)
The hemagglutinins from the spawn of the water snail Biomphalaria glabrata were isolated by affinity chromatography on hog gastric mucin coupled to Sepharose 4B. The N-acetyl-d-glucosamine eluate (0.1 M) was fractionated further on Bio-Gel P-300, yielding two fractions. Fraction 1 had an M"r of 350 000 and displayed one band in immunoelectrophoresis, but was heterogeneous in discontinuous electrophoresis. It agglutinated human red blood cells with A"1 and B specificity at concentrations of 12 and 72 μg nitrogen/ml, respectively. Fraction 2 had an M"r on gel filtration of 67 000 and was homogeneous in immuno- and polyacrylamide electrophoresis, and in isoelectrofocusing. It is composed of three subunits with M"r of 17 000 and one smaller subunit of 15 000. This fraction (lectin I) is a glycoprotein containing 6% hexoses and 2.5% hexosamines. For minimal agglutination of human A"1 and B red blood cells 2.4 and 72.0 μg nitrogen/ml, respectively, of lectin I were required. O red blood cells were not agglutinated. Lectin I precipitated well with a human blood group substance of A"1 specificity, moderately with a B- and poorly with an H-substance. Precipitin-inhibition studies revealed that among other sugars N-acetylneuraminic acid was the most potent inhibitor. Immunofluorescence studies confirmed the good interaction of lectin I with receptors of A"1 and B erythrocytes and the failure of lectin I to attach to O-erythrocytes. Since N-acetylneuraminic acid is present on the cell surface of all human erythrocytes, it cannot be the dominant part of the receptor for the B. glabrata lectin I, despite its effectiveness as an inhibitor.
http://linkinghub.elsevier.com/retrieve/pii/0167-4838(83)90246-7
Keywords: W; V; WW-YZ