RAPOPORT, H.S.*; SHADWICK, R.E.: A keratin-like gastropod biomaterial used to clarify the mechanical models of keratin

&alpha-keratin fibers exhibit fairly interesting mechanical properties with a fully recoverable region of apparent failure (as evidenced by an order-of-magnitude decrease in elastic modulus) at strains on the order of 2%-5%. For the past 30+ years, variations of models seeking to explain these unusual mechanical characteristics have centered on aspects of secondary, tertiary, and quaternary structure. Currently, three popular competing models exist in the literature: Wortmannn and Zahn (W/Z), Feughelman (F94), and Chapman and Hearle (C/H). Here, I present an unusual keratin-like protein produced by marine snails (whelks). Both materials are fiber-based with structural similarities at the secondary and tertiary levels. The materials differ, however, in bulk structural arrangement. Still, the materials exhibit the same mechanical response to strain. Thus I use this interesting material to argue the validity of the competing models present in the literature for keratin.