The proteins of normal and psoriatic human epidermis

Hunter, Irene (1977) The proteins of normal and psoriatic human epidermis. MSc(R) thesis, University of Glasgow.

Abstract

The epidermal fibrous protein has been successfully extracted from the cornified cells of human plantar callus and stratum corneum with buffered urea solutions. The proteins of these two horny cell layers are structurally dissimilar and differ also from the fibrous proteins prekeratin, of the living cell layers. Human prekeratin is a multichain protein, and on polyacrylamide gels, three different polypeptide chains of molecular weights 70,000, 63,000 and 55,000 can be detected. All three of these chains are present in plantar callus, but there is a much higher proportion of the 70,000 molecular weight chain than in purified prekeratin. The 55,000 molecular weight chain is not present in stratum corneum. The polypeptide chains of the fibrous protein are the major constituents of both living and horny cell layers 5, but in extracts of foreskin epidermis a prominent pale-blue staining polypeptide has been detected. It has a molecular weight of 45,000 and is apparently unrelated to any previously extracted epidermal protein. The 55,000 and 63,000 molecular weight chains of the fibrous protein are prominent in psoriatic scales, but the 70,000 molecular weight chain is deficient and occasionally absent. The psoriatic fibrous protein is structurally abnormal resembling neither the protein of callus nor stratum corneum. Effective treatment of psoriasis causes changes in the fibrous protein, finally resulting in a normal structure. The uninvolved callus and stratum corneum of psoriatics have fibrous protein structures indistinguishable from those of the normal tissues. There is an overall similarity between the amino acid analyses of callus, stratum corneum, psoriatic scale and human prekeratin, apart from differences in their contents of glycine and serine. Differences in the tissue contents of these two amino acids appear to be related to changes in the intensity of the 70,000 molecular weight chain of the fibrous protein. Varying the conditions of extraction of the horny cell layers alters the amount hut not the polypeptide composition of the isolated material. In the absence of a reducing agent, a large amount of fibrous protein polypeptides are released from psoriatic scale but only a very small amount from plantar callus. These results are discussed in relation to normal keratinisation and to the defects in this process in psoriatic epidermis.

• Item Type: Thesis (MSc(R))
• Qualification Level: Masters
• Additional Information: Adviser: David Skerrow
• Keywords: Molecular biology
• Date of Award: 1977
• Depositing User: Enlighten Team
• Unique ID: glathesis:1977-72083
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 17 May 2019 13:05
• Last Modified: 17 May 2019 13:05
• URI: https://theses.gla.ac.uk/id/eprint/72083