Psophocarpus tetragonolobus(psophocarpinB1, a storage protein with chymotrypsin inhibitory activity), PTL I lectin is isolated from winged bean seeds and purified by affinity chromatography. The seed contains two lectins in which PTL I is thebasicof the two, with an isoelectric point greater than pH 9.5 and a molecular weight of 58,000. PTL I is a dimeric glycoprotein with specificity to GalNAc, eluting the sugar GalNAc.
This lectin agglutinates trypsinized rabbit and human type A and B erythrocytes but not trypsinized human type O erythrocytes. PTL I recognizes blood group A-substance derived oligosaccharides such as trisaccharide GalNAcÃ¯Â±1-3GalÃ¯_1-4Glc. Studies on inhibition assays of lectin-blood group A precipitation demonstrated that substance-derived oligosaccharides were the best inhibitors and had the common structure of D-GalNAc alpha(1,3)D-Gal-(beta 1,3/4) to a D-Glc, and about 8 and 4 times more active than D-GalNAc and D-GalNAc alpha(1,3)D-Gal, respectively.
Reports on the thermodynamics and kinetics of the lectin suggest that it has an extended binding site, and its interactions with saccharides involvereorientationof water molecules.
This product comes in a lyophilized powder form and is stored at -20Ã«ï¿½C.
Staining of mouse M-cells
Blood vessel staining of A and B group individuals
- Kortt, A. Purification and properties of the basic lectins from winged bean seed [Psophocarpus tetragonolobus(L.) DC].FEBS J. (1984) 138(3):519-525.
- Matsuda, T., et al. Carbohydrate binding specificity of the basic lectin from winged bean (Psophocarpus tetragonolobus).Mol Immunol.(1989) 26(2):189-95.
- Patanjali, S., et al. Erythrocyte-binding studies on an acidic lectin from winged bean (Psophocarpus tetragonolobus).Jbiochem. (1988) 252:625-631.
- Sharma, V., et al. Cloning and sequencing of the winged bean (Psophocarpus tetragonolobus)basic agglutinin (WBA I):presenceof second glycosylation site and its implications in quaternary structure.FEBS J.(1996) 389:289-292.