Fibril and hence the whole muscle. Elastin is a fibrous protein common in various soft tissues, like skin, blood vessels and lung tissue. Each monomer connects with each other, forming a 3D network, with ability to endure over 200% strain before deformation. Keratin is a structural protein mainly found in hair, nails, hooves, horns, quills. Basically keratin is formed by polypeptide chains, which coil into α-helices with sulfur cross-links or bond into β-sheets linked by hydrogen bonding. β-keratin, which is tougher than α-conformation, is more common in birds and reptiles. Resilin is an elastomeric insect protein, consisting of both α-helices and
The dogs and the lion's skin The dogs and the lion's skin The dogs and the lion's skin is a fable ascribed to Aesop and is numbered 406 in the Perry Index. However, it is only found in a mediaeval Greek manuscript claiming to be a translation from the Syriac (Syntipas, Fable 19). The story relates how some dogs, finding the skin of a lion, began to tear it to pieces. Seeing them, a passing fox remarked, "If this lion were alive, you would soon find out that his claws were stronger than your teeth." The moral in the original commented that "the fable is for