A statistical mechanical model for antiparallel beta-sheet/coil equilibrium.

In this paper, a simple statistical mechanical model for the antiparallel beta-sheet/coil equilibrium is constructed. It is based on the transfer matrix method, which has been widely used in the helix/coil transition theory. However, to correctly represent the structure of antiparallel beta-sheet, we have to extend the former numerical matrix to an 11x11 operator one. All calculation rules of the operators are given, which can be automatically done by computers. In the end, the partition functions for homopolymers of varied lengths, applications to experimental data, and detailed antiparallel beta-sheet/coil transition are shown.