Playing with words, then, it is as if the horn that is the molecule gets transformed into the horn that is the horn that gets transformed into the horn that is blown.
A similar configuration exists at a molecular level. The keratin protein is made up of helical amino acids that are then coiled and paired into protofilaments that are, in turn, twisted into long, strong filaments. This structure is called a coiled coil or a superhelix.
Rope has a similar structure in which small fibers are twisted into twine that is twisted into plies and then, finally into a rope. While each small fiber may be fragile, the twisting puts lateral pressure on the fibers to squeeze them together so friction (or molecular bonds) can hold hold them together tightly. By reversing the direction of twist at each stage, all the individual fibers end up aligned along the length of the rope, providing maximum structural integrity. More, the forces of the opposing twists cancel each other out so their is not a tendency to unwind.
As with rope, the superhelix or "super twisted coiled coil" structure of keratin imparts great strength to the body parts made of the proteins.
|Keratin structure from PubMed|
The protein in bone is collagen and also has a superhelical form, a triple helix.