Introduction to Protein Structure
Secondary Structure -- Alpha Helix
The backbone of an alpha helix (shown in color below) is arranged in a spiral similar to that seen on a cork screw. Notice how the sidechains (shown in dark grey) stick more-or-less straight out from the backbone.
The alpha helix is stabilized by hydrogen bonds between the carbonyl oxygen of one amino acid and the backbone nitrogen of a second amino acid located four positions away. Turn on the "highlight" in the figure below to color every fourth residue the same color.
This alpha helix consists of residues 4 to 15 in lysozyme isolated from chicken egg white.
Copyright © 1998, 1999, 2007 by Frank R. Gorga; Page maintained by F.R. Gorga; Last updated: 12-Mar-2007