alpha helix

Last reviewed 01/2018

The alpha helix is a structural motif of proteins. It forms spontaneously as part of the secondary level of organization within proteins.

It consists of the primary polypeptide chain forming a spiral. There are approximately 3.5 amino acids per turn of the spiral. The structure is stabilized by hydrogen bonding between side groups.

Alpha helices are present within:

  • keratin
  • myosin
  • fibrin
  • collagen