Temperature effect on affinity chromatography of two lectins from the seeds of Ricinus communis

Specific adsorption capacity of Sepharose 4B in affinity chromatography for two purified galactose-binding lectins, designated as III_L and III_H, from the seed of Ricinus communis (castor bean) was measured from 7 to 24°C. The adsorption coefficients for these two protein fractions as a function of temperature were also obtained. It was found that there is a characteristic transition of adsorption coefficient at 18°C for both lectins. Adsorption coefficients between Sepharose 4B and these two lectins were also expressed in terms of ΔG, ΔH, andΔS. It is suggested that the difference in the temperature dependence of the binding energy of these two lectins may be used for their separation at selected temperature.