Separation of proteins from phenols in cereal leaf extract by hydrophobic interaction — ammonium sulfate fractionation

Two methods have been developed to separate plant extract water-soluble proteins from secondary metabolites, in particular from plant phenolic compounds. The first method is chromatography of a plant extract on Toyopearl HW60 in ammonium sulfate solution. The second is differential precipitation of proteins and phenolic compounds with ammonium sulfate in the presence of polyethylene glycol at low concentrations. Both methods were used for isolation of cytokinin-binding protein with a molecular mass of 70 kDa from maize (Zea mays) coleoptiles and gave good results. These techniques can be used for isolation of any water-soluble protein from plants.