Which of the following statements about α-keratins is FALSE?
1) Individual molecules are α-helical.
2) They include a major class of protein that comprises hair, fingernails and animal skin.
3) There is a strip of contiguous hydrophobic surface making a shallow spiral around the helix.
4) Pairs of α-helices twist about each other in a coiled-coil structure held together entirely by hydrophobic interactions.
5) They include a small globular regions covalently linked to the surface.
