Noun
alpha helix (plural alpha helices or alpha helixes)
English Wikipedia has an article on:alpha helixWikipedia
A secondary structure found in many proteins, in which the amino acids are arranged in a coil, or helix, with almost no free space on the inside and all side chains being pointed towards the outside
alpha-helix
Given Pauling's recent success in discovering the Alpha helix, they feared that Pauling might also be the first to determine the structure of DNA. Source: Internet
Linus Pauling was the first to identify citation the 3.6 amino acids per helix turn ratio of the Alpha helix. Source: Internet