X-ray studies of the distribution of protein chain types in the vertebrate epidermis

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Abstract

  • 1.

    1. The chief structural protein of the vertebrate epidermis, as observed in X-ray diffraction studies, is of the α-keratin type.

  • 2.

    2. Only in Amniota are lipoid constituents visible in the diffraction patterns of the epidermis: an exception is the parakeratotic epidermis from the upper lip of the cow. These lipoids seem to be associated with the keratohyalin - eleidin system.

  • 3.

    3. In Reptiles and Birds fibrous molecules of the feather keratin type are predominant in the hard keratin structures. Detailed studies of the feather follicle system show that the stratum intermedium synthesises feather keratin and apparently no α-keratin, while the outermost layers of the ‘stratum corneum’ and the stratum cylindricum synthesise mainly the α-keratin type.

  • 4.

    4. Reptilian and Avian keratins have many features in common but differ in detail.

  • 5.

    5. In regions of the epidermis of reptiles and birds where strength and flexibility are required the α-protein structure is stongly predominant.

Résumé

  • 1.

    1. La principale protéine de structure de l'épiderme des vertébrates d'après les résultats obtenus par la diffraction des rayons X, appartient au type α-kératine.

  • 2.

    2. Le spectre de diffraction de l'épiderme met en évidence des constituants lipoïdiques uniquement dans l'amnios. Seul, fait exception l'épiderme parakératique de la lèvre supériure de la vache. Ses lipoides semblent être associés au système kérato-hyaline-éléidine.

  • 3.

    3. Chez les reptiles et les oiseaux, les molécules du type kératine des plumes prédominant dans la structure de la kératine solide. Des observations détaillées du système du follicule des plumes montre que le “stratum intermedium” synthétise la kératine des plumes et non pas l'α-kératine, alors que les couches externes du “stratum corneum” et du “stratum cylindricum” synthétisent surtout le type α-kératine.

  • 4.

    4. Les kératines des reptiles et des oiseaux ont beaucoup de points communs dans leur structure, mais diffèrent dans les détails.

  • 5.

    5. Dans les régions de l'épiderme des reptiles et des oiseaux, qui nécessitent de la force et de la flexibilité, c'est la structure α-proteine qui prédomine.

Zusammenfassung

  • 1.

    1. Das hauptsächliche Struktureiweiss der Wirbeltierepidermis ist,wei bei Röntgenstrahlffraktionsuntersuchungen beobachtet wurde, vom α-Keratintyp.

  • 2.

    2. Nur bei Amniota sind Lipoidbestandteile in den Beugungsgittern der Epidermis sichtbar; eine Ausnahme bietet die parakeratotishe Epidermis der Oberlippe des Rinds. Diese Lipoide scheinen mit dem Keratohyalin-Eleidinsystem assoziiert zu sein.

  • 3.

    3. Bei Reptillien und Vögeln sind Fasermoleküle des Federkeratintypes bei den harten Keratinstrukturen vorherrschend. Detaillierte Untersuchungen des Federkollikelsystems zeigen, dass das stratum intermedium Federkeratin und offensichtlich kein α-Keratin synthetisiert, während die äusserten Schichten des “stratum corneum” und das stratum cylindricum hauptsächlich den α-Keratintyp synthertisieren.

  • 4.

    4. Reptilien - und Vögelkeratine haben viele Eigenschaften gemeinsam, unterscheiden sich aber in Details.

  • 5.

    5. In den Gebeiten der Reptil- und Vogelepidermis, wo Stärke und Beugsamkeit benötigt werden, herrscht die α-Eiweisstruktur stark vor.

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