Precursor keratin protein from human epidermis.

Prekeratin has been isolated from human epidermis using the method of Matoltsy for bovine nose epidermis. Analysis by sedimentation equilibrium indicates that human prekeratin is heterogeneous in solution. The molecular weight range is from about 200 X 10(3) to at least 2 X 10(6). Polyacrylamide gel electrophoresis shows three polypeptide chains of molecular weights 65,000 60,000 and 58,000. A lower than average ratio of polar/apolar amino acid residues suggests that hydrophobic interactions are important for stability.