Immunolocalization and characterization of cornification proteins in snake epidermis

Abstract

Little is known about specific proteins involved in keratinization of the epidermis of snakes, which is composed of alternating β- and α-keratin layers. Using immunological techniques (immunocytochemistry and immunoblotting), the present study reports the presence in snake epidermis of proteins with epitopes that cross-react with certain mammalian cornification proteins (loricrin, filaggrin, sciellin, transglutaminase) and chick β-keratin. α-keratins were found in all epidermal layers except in the hard β- and α-layers. β-keratins were exclusively present in the oberhautchen and β-layer. After extraction and electrophoresis, α-keratins of 40-67 kDa in molecular weights were found. Loricrin-like proteins recorded molecular weights of 33, 50, and 58 kDa; sciellin, 55 and 62 kDa; filaggrin-like, 52 and 65 kDa; and transglutaminase, 45, 50, and 56 kDa. These results suggest that α-layers of snake epidermis utilize proteins with common epitopes to those present during cornification of mammalian epidermis. The β-keratin antibody on extracts from whole snake epidermis showed a strong cross-reactive band at 13-16 kDa. No cross-reactivity was seen using an antibody against feather β-keratin, indicating absence of a common epitope between snake and feather keratins. © 2005 Wiley-Liss, Inc.