Immunolocalization of specific beta-proteins in pad lamellae of the digits in the lizard Anolis carolinensis suggests that cysteine-rich beta-proteins provides flexibility.

Knowledge of beta-protein (beta-keratin) sequences in Anolis carolinensis facilitates the localization of specific sites in the skin of this lizard. The epidermal distribution of two new beta-proteins (betakeratins), HgGC8 and HgG13, has been analyzed by Western blotting, light and ultrastructural immunocytochemistry. HgGC8 includes 16 kDa members of the glycine-cysteine medium-rich subfamily and is mainly expressed in the beta-layer of adhesive setae but not in the setae. HgGC8 is absent in other epidermal layers of the setae and is weakly expressed in the beta-layer of other scales. HgG13 comprises members of 17-kDa glycine-rich proteins and is absent in the setae, diffusely distributed in the beta layer of digital scales and barely present in the beta-layer of other scales. It appears that the specialized glycine-cysteine medium rich beta-proteins such as HgGC8 in the beta-layer, and of HgGC10 and HgGC3 in both alpha- and betalayers, are key proteins in the formation of the flexible epidermal layers involved in the function of these modified scales in adaptation to contact and adhesion on surfaces.