Hydrophobic interaction chromatography on non-charged Sepharose derivatives. Binding of a model protein, related to ionic strength, hydrophobicity of the substituent, and degree of substitution (determined by NMR).

A series of agarose gels, substituted with hydrophobic groups, has been synthesized and used for binding studies with the coloured model protein, phycoerythrin. The degrees of substitution for the derivatives can easily be estimated with proton magnetic resonance (NMR). It has been found that the capacity of the derivatives for phycoerythrin increases with increasing hydrophobicity of the substituent, degree of substitution and increasing ionic strength. For column experiments the degree of substitution should lie in the range 40-100 mmol substituent/mol galactose. When it is excessively high, the flow characteristics of the columns are unsatisfactory and difficulties to achieve complete desorption may arise.