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 Keg of Nails is a replica of a keg used to ship nails. The exchange is believed to have been initiated by fraternity chapters on the UC and U of L campuses, signifying that the winning players in the game were "tough as nails." The present keg is actually a replacement for the original award, which was misplaced by Louisville, lost during some construction of office facilities. It is adorned with the logos of both schools and the scores of the series games. The rivalry went on hiatus following the 2013 season, as Louisville moved to the Atlantic Coast Conference on July 1,