Concanavalin A, a receptor protein with apparently co-operative binding characteristics

Abstract

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.

Lectin–carbohydrate interactions on nanoporous gold monoliths

“…Con A is a tetrameric lectin that cooperatively binds mannose or glucose containing carbohydrate structures. 108,109 The binding of Con A to the unmodified np-Au was studied under flow-conditions, and it was estimated by TGA that 0.3200 mg of Con A was adsorbed onto the surface of bare np-Au from a solution of concentration 1.0 mg mL −1 after 3.5 hours at 1.0 mL min −1 . The diffusion coefficient for Con A at pH 7.0 has been reported as D 25,w = 5.7 × 10 −7 cm 2 s −1 , at 298 K and corrected for the viscosity of water.…”