Carbohydrate-lectin interactions assessed by surface plasmon resonance

The specificity, the strength, the kinetics and some thermodynamic parameters of sugar-protein interactions are easily assessed by surface plasmon resonance (SPR). This paper intends to present both theoretical and practical considerations. This includes: the principle of SPR, the analysis according to Langmuir and Scatchard, the problems linked either to mass transport limitation, to the heterogeneity of the immobilized ligand density or to the non-linearity due to cluster effects. The non-linearity may be taken into account by either one of two ways: the fractal or the Sips approaches that have been developed with the aim of linearizing the data. In addition, selected data obtained by using either immobilized carbohydrates or immobilized lectins are summarized. The SPR has also been found useful to collect information concerning oligosaccharide structure as well as lectin-sugar specificity and to develop new tools with medical applications. Finally, a series of practical considerations are gathered in the hope of avoiding some of the common pitfalls arising in sugar-lectin interaction studies based on the use of SPR.