a beta pleated sheet is a pleated structure that
is composed of the C-C-N-C-C backbone of a polypeptide.
In the figure above, each chain of CCNCC... has a N to C
polarity in the direction opposite to that of its neighbor. The line on
the left has the N-to-C polarity from top to bottom. The line in
the middle has the N-to-C polarity from bottom to top. The line on
the far right has the N-to-C polarity from top to bottom. These chains
are said to to be antiparallel because they run in the opposite directions.
If the chains run in the same N-C direction they are saild to be parallel.
The beta pleated sheet structure is stabilized by hydrogen bonds between
the different chains.
return to 3D structure of proteins