title: Urea-extractable protein from human epidermis.
abstract: The major protein fraction extracted from human epidermis by urea has the following characteristics: (1) A molecular weight of approximately 600 000. (2) A copper content of 0.03% giving a minimum molecular weight of 212 000. (3) A non-protein moiety indicated by (a) protein/dry weight ratio (b) anomalous ultraviolet absorption spectrum (c) high-voltage electrophoresis after mild alkaline or acid treatment (d) an excess of imidazole groups by Pauly reaction compared with the number of histidine residues by amino acid analysis. The non-protein component is not urocanic acid or RNA as has been reported (Bernstein, I.A. (1970), J. Soc. Cosmet, Chem. 21, 583-594 and Sibrack, L. A., Gray, R. H. and Bernstein, I. A. (1974), J. Invest. Dermatol. 62, 394-405). (4) The presence of interchain disulphide linkages indicated by polyacrylamide gel electrophoresis in sodium dodecyl sulphate with and without beta-mercaptoethanol. (5) Polyacrylamide gel electrophoresis in presence and absence of 6 M urea suggests that aggregates are broken down in urea.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D003300:Copper / Q000032:analysis; D006639:Histidine / Q000378:metabolism; D006801:Humans; D008667:Metalloproteins / Q000096:biosynthesis / Q000302:isolation & purification; D008970:Molecular Weight; D011485:Protein Binding; D012867:Skin / Q000032:analysis* / Q000378:metabolism; D013056:Spectrophotometry, Ultraviolet; D014508:Urea
chemical_list: D000596:Amino Acids; D008667:Metalloproteins; D006639:Histidine; D003300:Copper; D014508:Urea