Quarterly Reviews of Biophysics 55, e7, 1–10. https://doi.org/10.1017/S0033583522000063

Abstract

 Linus Pauling in 1950 published a three-dimensional model for a universal protein secondary structure motif which he initially called the alpha-spiral. Jack Dunitz, then a postdoc in Pauling's lab suggested to Pauling that the term helix is more accurate than spiral when describing the right-handed peptide and protein coiled structures. Pauling agreed, hence the rise of the alpha-helix, and, by extension, the ‘double helix’ structure of DNA. Although structural biologists and protein chemists are familiar with varying polar and apolar characters of amino acids in alpha-helices, to non-experts the three chemically distinct alpha-helix types classified here may hide in plain sight.