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The structural protein of reptilian scales

1974; Wiley; Volume: 187; Issue: 2 Linguagem: Inglês

10.1002/jez.1401870212

1097-010X

Howard Baden, Sylvester Sviokla, Irwin Roth,

Advancements in Transdermal Drug Delivery

Abstract Previous studies of reptilian epidermis have shown that scales contain both a and feather fibrous proteins. The outer stratum (feather) and inner stratum (a) of snake (Boa constrictor) scales were separated and the tissue extracted with 6 M urea in 0.1 M Tris, pH 9.0, with 0.1 M mercaptoethanol. Following alkylation to the S‐carboxymethyl derivatives (SCM), the proteins were separated on the basis of their solubility at pH 4.5. X‐ray diffraction analysis indicated that pH 4.5 insoluble proteins represented the fibrous proteins while the soluble ones had the characteristics of matrix material. Disc electrophoretic patterns and amino acid analyses of the two types of fibrous proteins were different while those of the matrix proteins from both strata appeared to be very similar. The epidermal proteins of shell (feather) and extremity (a) skin from turtle (Pseudemys) were similarly isolated and shown to have different amino acid compositions. Although separation of the various components by differences in their solubility at pH 4.5 was not possible, a comparison of electrophoretic patterns suggested that the proteins extracted from the epidermis of the shell and extremity skin had different fibrous but similar matrix proteins. These studies indicated a strong similarity between reptilian scales and hair, where fibrous and matrix proteins are present and are separable on the basis of the solubility of their SCM derivatives. Although the a and feather fibrous proteins form filaments of very different size, it appears that they are associated with similar matrix proteins.