Immunocytochemistry indicates that glycine‐rich beta‐proteins are present in the beta‐layer,while cysteine‐rich beta‐proteins are present in beta‐ and alpha‐layers of snake epidermis

Immunolocalization of glycine‐rich and cysteine–glycine‐medium‐rich beta‐proteins (Beta‐keratins) in snake epidermis indicates a different distribution between beta‐ and alpha‐layers. Acta Zoologica, Stockholm. The epidermis of snakes consists of hard beta‐keratin layers alternated with softer and pliable alpha‐keratin layers. Using Western blot, light and ultrastructural immunolocalization, we have analyzed the distribution of two specific beta‐proteins (formerly beta‐keratins) in the epidermis of snakes. The study indicates that the antibody HgG5, recognizing glycine‐rich beta‐proteins of 12–15 kDa, is poorly or not reactive with the beta‐layer of snake epidermis. This suggests that glycine‐rich proteins similar to those present in lizards are altered during maturation of the beta‐layer. Conversely, a glycine–cysteine‐medium‐rich beta‐protein (HgGC10) of 10–12 kDa is present in beta‐ and alpha‐layers, but it is reduced or disappears in precorneous and suprabasal cells destined to give rise to beta‐ and alpha‐cells. Together with the previous studies on reptilian epidermis, the present results suggest that beta‐proteins rich in glycine mainly accumulate on a scaffold of alpha‐keratin producing a resistant and hydrophobic beta‐layer. Conversely, beta‐proteins lower in glycine but higher in cysteine accumulate on alpha‐keratin filaments present in beta‐ and alpha‐layers producing resistant but more pliable layers.