Concanavalin A, a receptor protein with apparently co-operative binding characteristics.
Laser nephelometry is a suitable technique for the quantitative determination and differentiation of both lectins and glycoconjugates in the low-picomolar range. Simultaneously this method renders possible investigations on the specificity and mode of interaction between lectins and different ligands. The results demonstrate that the degree of co-operativity between concanavalin A and the respective glycoconjugate is dependent on the presence of hydrophobic binding sites and can be substantially altered by conformational changes of the ligand. The transition from apotransferrin to Fe3+-transferrin induces a transformation of the sigmoidal-shaped binding curve to a hyperbolic one. Hence, at low concentrations, Fe3+-transferrin is bound far better than apotransferrin, whereas maximal binding is nearly identical. After removal of N-acetylneuraminate, concanavalin A is less efficient in differentiating between the Fe3+-charged and Fe3+-free (apo) forms of transferrin.
D001059:Apoproteins / Q000378:metabolism; D001665:Binding Sites; D003208:Concanavalin A / Q000378:metabolism*; D005290:Ferric Compounds / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism; D007700:Kinetics; D011485:Protein Binding; D011487:Protein Conformation; D014168:Transferrin / Q000378:metabolism; D000509:alpha-Fetoproteins / Q000378:metabolism
D001059:Apoproteins; D005290:Ferric Compounds; D014168:Transferrin; D000509:alpha-Fetoproteins; D003208:Concanavalin A; D006003:Glycogen