(A) Polypeptide model. The orientations of perfectly planar and rigid peptide bonds are given by the orthonormal triplets (x, y, z), with z pointing along the Cα-Cα direction. Other peptide bond atoms lie in the plane yz. The position of the side-chain atoms R is specified by the vectors n and c. (B) Local Metropolis moves. Two types of moves are used in this work: a crankshaft rotation around the line connecting 2 Cα atoms in the middle of the chain, and a random rotation at the termini around a random axis passing through the Cα atom. From Podtelezhnikov and Wild (2005) .
Podtelezhnikov and Wild Source Code for Biology and Medicine 2008 3:12 doi:10.1186/1751-0473-3-12