Probing protein surface accessibility of amino acid substitutions using hydrophobic interaction chromatography

Hydrophobic interaction chromatography (HIC) has been used to determine the influence of amino acid substitutions on protein retention and thereby their accessibility on the protein surface. The retentions of mutants of green fluorescent protein (GFPuv) and human hemoglobin (Hb) were studied on multimodal HIC media and compared to the hydrophobicities from known hydrophobicity scales with respect to the accessible surface area. For GFPuv, the theoretical and experimental results of three hydrophobicity scales correlated well (R2 > 0.85), which clearly indicate that the results can be used for protein retention prediction as well as probing surface properties of protein variants.