Alpha Helix Protein Structure Model

This Indigo® alpha helix model consists of 20 amino acid cores with a right handed chirality (clockwise spiral). Alpha helices are common in important biological proteins such as keratin (skin), hemoglobin (blood), myoglobin (muscle), & collagen (various tissues).

This model shows protein secondary structure based on 3.6 amino acid residues per turn & closely matches the scale of pitch distance 5.4 Å (angstroms), rise per residue of 1.5 Å & helix diameter of 6 Å. The backbone consists solely of alpha carbons and amino & carboxyl groups.

The “R” groups are indicated with a univalent green atom & face outward where they interact with other structures such as the major groove of our 12 base pair DNA double helix model.These "R" groups can be substituted with additional parts to show the most commonly occurring amino acid residues methionine, alanine, leucine, glutamate and lysine in the alpha helix polypeptide chain. These extra parts can make the steric hindrance more obvious when compared to the minor groove.

50mm bonds with white inserts represent the amide hydrogen atoms (N−HN-HN−H) of residues hydrogen bonded to carbonyl oxygen atoms (C=OC=OC=O) of another residue. This makes it clearer how the alpha helix structure is kept stable through these bonds (n to n+4) that are 4 residues away in the amino acid sequence.