The chemical nature of keratohyalin granules of the epidermis.
Keratohyalin granules were isolated in the native form from the epidermis of newborn rats by the use of citric acid and a detergent. The isolated granules revealed a fine granular substructure in the electron microscope similar to that seen in situ. Analyses of amino acids by automated column-chromatography showed that proline and cystine are present in large proportions whereas histidine is present in a small amount. Accordingly, it was concluded that keratohyalin represents a sulfur-rich amorphous precursor of the horny cell content, rather than a sulfur-poor side product of the keratinization process, or a unique histidine-rich protein as proposed by in situ histochemical and radioautographic studies.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001322:Autoanalysis; D002845:Chromatography; D003553:Cystine / Q000032:analysis
D000596:Amino Acids; D003553:Cystine