A simplified method for studying fibrous proteins in psoriatic scales obtained by tape stripping

Polyacrylamide gel electrophoretic investigations were carried out on solubilized proteins from psoriatic and normal stratum corneum obtained by adhesive tape stripping. The proteins in the scales adhering to the tape were solubilized by incubating the tape in 1% sodium dodecyl sulphate (SDS) solution. The electrophoretic behaviour of these solubilized proteins on SDS-polyacrylamide gel was compared with the alpha-fibrous proteins (keratin) of callus. The proteins isolated from callus of normal human heel showed six main bands which were similar to those of the keratin isolated by the 8 M urea-mercaptoethanol method. The lesional skin of forty-five psoriatic patients consistently showed nine main bands on polyacrylamide gels, but only two main bands were observed in the non-lesional, non-heel skin. Six of these nine bands had mobilities and relative intensities almost identical with those of alpha-keratin extracted by the mercaptoethanol method, but the other three bands had greater mobilities on the gels. These results suggest that this technique may have considerable potential for studying changes in alpha-keratin in patients with psoriasis and other disorders of keratinization.